Many stale and invalid shares for a month now
Hi, i'm mining the Haven algo (bloc) and i notive since the last update that i'm starting to have stale shares (~5%) and few days ago i started to have invalid shares (~1%). 

Thank you for your help.

Here is my log form early yesterday (check bold) : 

 * ABOUT        XMRig-AMD/2.14.6 MSVC/2017
 * LIBS         libuv/1.31.0 OpenCL/2.0 OpenSSL/1.1.1c microhttpd/0.9.63
 * CPU          Intel(R) Celeron(R) CPU G3930 @ 2.90GHz x64 AES
 * ALGO         cryptonight-heavy, donate=1%
 * POOL #1      pool.bloc.hashvault.pro:6666 variant 0
 * COMMANDS     hashrate, pause, resume
[2019-10-06 12:58:01] compiling code and initializing GPUs. This will take a while...
[2019-10-06 12:58:05] found AMD platform index: 1, name: Advanced Micro Devices, Inc.
[2019-10-06 12:58:05] #00, GPU #00 Radeon RX 580 Series (Ellesmere), i:936 (8/256), si:2/2, u:8, cu:36
[2019-10-06 12:58:05]              3.66/3.95/8 GB
[2019-10-06 12:58:06] #01, GPU #00 Radeon RX 580 Series (Ellesmere), i:936 (8/256), si:2/2, u:8, cu:36
[2019-10-06 12:58:06]              3.66/3.95/8 GB
[2019-10-06 12:58:06] #02, GPU #01 Radeon RX 580 Series (Ellesmere), i:936 (8/256), si:2/2, u:8, cu:36
[2019-10-06 12:58:06]              3.66/3.95/8 GB
[2019-10-06 12:58:06] #03, GPU #01 Radeon RX 580 Series (Ellesmere), i:936 (8/256), si:2/2, u:8, cu:36
[2019-10-06 12:58:06]              3.66/3.95/8 GB
[2019-10-06 12:58:06] #04, GPU #02 Radeon RX 580 Series (Ellesmere), i:936 (8/256), si:2/2, u:8, cu:36
[2019-10-06 12:58:06]              3.66/3.95/8 GB
[2019-10-06 12:58:07] #05, GPU #02 Radeon RX 580 Series (Ellesmere), i:936 (8/256), si:2/2, u:8, cu:36
[2019-10-06 12:58:07]              3.66/3.95/8 GB
[2019-10-06 12:58:07] #06, GPU #03 Radeon RX 580 Series (Ellesmere), i:936 (8/256), si:2/2, u:8, cu:36
[2019-10-06 12:58:07]              3.66/3.95/8 GB
[2019-10-06 12:58:08] #07, GPU #03 Radeon RX 580 Series (Ellesmere), i:936 (8/256), si:2/2, u:8, cu:36
[2019-10-06 12:58:08]              3.66/3.95/8 GB
[2019-10-06 12:58:08] #08, GPU #04 Radeon RX 580 Series (Ellesmere), i:936 (8/256), si:2/2, u:8, cu:36
[2019-10-06 12:58:08]              3.66/3.95/8 GB
[2019-10-06 12:58:08] #09, GPU #04 Radeon RX 580 Series (Ellesmere), i:936 (8/256), si:2/2, u:8, cu:36
[2019-10-06 12:58:08]              3.66/3.95/8 GB
[2019-10-06 12:58:08] #10, GPU #05 Radeon RX 580 Series (Ellesmere), i:936 (8/256), si:2/2, u:8, cu:36
[2019-10-06 12:58:08]              3.66/3.95/8 GB
[2019-10-06 12:58:09] #11, GPU #05 Radeon RX 580 Series (Ellesmere), i:936 (8/256), si:2/2, u:8, cu:36
[2019-10-06 12:58:09]              3.66/3.95/8 GB
[2019-10-06 12:58:09] use pool pool.bloc.hashvault.pro:6666  131.153.56.98
[2019-10-06 12:58:09] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348158
[2019-10-06 12:58:33] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348158
[2019-10-06 12:59:05] speed 10s/60s/15m 5318.4 n/a n/a H/s max 5318.6 H/s
[2019-10-06 12:59:08] accepted (1/0) diff 150000 (67 ms)
[2019-10-06 12:59:12] accepted (2/0) diff 150000 (76 ms)
[2019-10-06 12:59:41] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348159
**[2019-10-06 12:59:43] rejected (2/1) diff 150000 "Stale share for height 348158. It's late for 1463 ms" (29 ms)**
[2019-10-06 12:59:46] accepted (3/1) diff 150000 (63 ms)
[2019-10-06 13:00:04] accepted (4/1) diff 150000 (78 ms)
[2019-10-06 13:00:05] speed 10s/60s/15m 5317.9 5318.2 n/a H/s max 5318.6 H/s
[2019-10-06 13:00:41] accepted (5/1) diff 150000 (77 ms)
[2019-10-06 13:00:58] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348160
[2019-10-06 13:01:05] speed 10s/60s/15m 5318.8 5318.5 n/a H/s max 5318.7 H/s
[2019-10-06 13:01:22] accepted (6/1) diff 150000 (64 ms)
[2019-10-06 13:01:30] accepted (7/1) diff 150000 (69 ms)
[2019-10-06 13:02:05] speed 10s/60s/15m 5318.0 5318.5 n/a H/s max 5319.0 H/s
[2019-10-06 13:02:11] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348161
[2019-10-06 13:02:54] accepted (8/1) diff 150000 (65 ms)
[2019-10-06 13:02:54] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348162
[2019-10-06 13:03:05] speed 10s/60s/15m 5317.3 5311.2 n/a H/s max 5319.0 H/s
[2019-10-06 13:03:07] accepted (9/1) diff 150000 (66 ms)
[2019-10-06 13:03:20] accepted (10/1) diff 150000 (59 ms)
[2019-10-06 13:03:30] accepted (11/1) diff 150000 (73 ms)
[2019-10-06 13:03:42] accepted (12/1) diff 150000 (70 ms)
[2019-10-06 13:04:05] speed 10s/60s/15m 5318.2 5318.1 n/a H/s max 5319.0 H/s
[2019-10-06 13:04:13] accepted (13/1) diff 150000 (57 ms)
[2019-10-06 13:04:30] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348163
[2019-10-06 13:05:05] speed 10s/60s/15m 5318.0 5318.1 n/a H/s max 5319.0 H/s
[2019-10-06 13:05:17] accepted (14/1) diff 150000 (66 ms)
[2019-10-06 13:05:40] accepted (15/1) diff 150000 (73 ms)
[2019-10-06 13:05:45] accepted (16/1) diff 150000 (58 ms)
[2019-10-06 13:06:05] speed 10s/60s/15m 5317.9 5318.2 n/a H/s max 5319.0 H/s
[2019-10-06 13:06:13] accepted (17/1) diff 150000 (60 ms)
[2019-10-06 13:06:14] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348164
[2019-10-06 13:06:19] accepted (18/1) diff 150000 (62 ms)
[2019-10-06 13:06:50] accepted (19/1) diff 150000 (66 ms)
[2019-10-06 13:07:05] speed 10s/60s/15m 5318.4 5318.3 n/a H/s max 5319.0 H/s
[2019-10-06 13:07:17] accepted (20/1) diff 150000 (69 ms)
[2019-10-06 13:07:17] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348165
[2019-10-06 13:07:41] accepted (21/1) diff 150000 (79 ms)
[2019-10-06 13:07:43] accepted (22/1) diff 150000 (66 ms)
[2019-10-06 13:07:44] accepted (23/1) diff 150000 (63 ms)
[2019-10-06 13:08:05] speed 10s/60s/15m 5318.5 5317.5 n/a H/s max 5319.4 H/s
[2019-10-06 13:08:07] accepted (24/1) diff 150000 (64 ms)
[2019-10-06 13:08:29] accepted (25/1) diff 150000 (75 ms)
[2019-10-06 13:08:52] accepted (26/1) diff 150000 (66 ms)
[2019-10-06 13:09:03] accepted (27/1) diff 150000 (64 ms)
[2019-10-06 13:09:05] speed 10s/60s/15m 5318.9 5318.2 n/a H/s max 5319.4 H/s
[2019-10-06 13:09:19] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348165
[2019-10-06 13:09:26] accepted (28/1) diff 150000 (80 ms)
[2019-10-06 13:09:49] accepted (29/1) diff 150000 (72 ms)
[2019-10-06 13:10:05] speed 10s/60s/15m 5318.4 5318.3 n/a H/s max 5319.4 H/s
[2019-10-06 13:10:06] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348166
[2019-10-06 13:10:30] accepted (30/1) diff 150000 (64 ms)
[2019-10-06 13:10:32] accepted (31/1) diff 150000 (65 ms)
[2019-10-06 13:10:54] accepted (32/1) diff 150000 (60 ms)
[2019-10-06 13:11:05] speed 10s/60s/15m 5318.4 5318.2 n/a H/s max 5319.4 H/s
[2019-10-06 13:11:26] accepted (33/1) diff 150000 (59 ms)
[2019-10-06 13:12:05] speed 10s/60s/15m 5318.3 5318.1 n/a H/s max 5319.4 H/s
[2019-10-06 13:12:07] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348166
[2019-10-06 13:12:59] accepted (34/1) diff 150000 (66 ms)
[2019-10-06 13:13:05] speed 10s/60s/15m 5318.8 5318.4 n/a H/s max 5319.4 H/s
[2019-10-06 13:13:17] accepted (35/1) diff 150000 (74 ms)
[2019-10-06 13:13:21] accepted (36/1) diff 150000 (67 ms)
[2019-10-06 13:13:26] accepted (37/1) diff 150000 (63 ms)
[2019-10-06 13:13:26] accepted (38/1) diff 150000 (58 ms)
[2019-10-06 13:14:05] speed 10s/60s/15m 5318.5 5318.1 5317.7 H/s max 5319.4 H/s
[2019-10-06 13:14:07] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348166
[2019-10-06 13:14:09] accepted (39/1) diff 150000 (71 ms)
[2019-10-06 13:14:59] accepted (40/1) diff 150000 (67 ms)
[2019-10-06 13:15:05] speed 10s/60s/15m 5317.9 5318.4 5317.8 H/s max 5319.4 H/s
[2019-10-06 13:15:26] accepted (41/1) diff 150000 (75 ms)
[2019-10-06 13:15:35] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348167
**[2019-10-06 13:15:35] rejected (41/2) diff 150000 "Stale share for height 348166. It's late for 499 ms" (38 ms)**
[2019-10-06 13:15:41] accepted (42/2) diff 150000 (66 ms)
[2019-10-06 13:16:05] speed 10s/60s/15m 5318.6 5318.3 5317.7 H/s max 5319.4 H/s
[2019-10-06 13:16:07] accepted (43/2) diff 150000 (66 ms)
[2019-10-06 13:16:20] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348168
[2019-10-06 13:16:34] accepted (44/2) diff 150000 (72 ms)
[2019-10-06 13:17:05] speed 10s/60s/15m 5318.2 5318.0 5317.7 H/s max 5319.4 H/s
[2019-10-06 13:17:31] accepted (45/2) diff 150000 (66 ms)
[2019-10-06 13:18:05] speed 10s/60s/15m 5318.5 5318.2 5318.2 H/s max 5319.4 H/s
[2019-10-06 13:18:20] accepted (46/2) diff 150000 (68 ms)
[2019-10-06 13:18:21] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348168
[2019-10-06 13:18:24] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348169
[2019-10-06 13:18:39] accepted (47/2) diff 150000 (67 ms)
[2019-10-06 13:18:39] accepted (48/2) diff 150000 (63 ms)
[2019-10-06 13:19:03] accepted (49/2) diff 150000 (70 ms)
[2019-10-06 13:19:05] speed 10s/60s/15m 5318.3 5318.2 5318.2 H/s max 5319.4 H/s
[2019-10-06 13:19:21] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348170
[2019-10-06 13:19:30] accepted (50/2) diff 150000 (72 ms)
[2019-10-06 13:20:05] speed 10s/60s/15m 5318.5 5318.3 5318.2 H/s max 5319.4 H/s
[2019-10-06 13:20:06] accepted (51/2) diff 150000 (63 ms)
[2019-10-06 13:21:05] speed 10s/60s/15m 5318.7 5318.4 5318.2 H/s max 5319.4 H/s
[2019-10-06 13:21:17] accepted (52/2) diff 150000 (72 ms)
[2019-10-06 13:21:20] accepted (53/2) diff 150000 (67 ms)
[2019-10-06 13:21:23] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348170
[2019-10-06 13:21:46] accepted (54/2) diff 150000 (72 ms)
[2019-10-06 13:22:05] speed 10s/60s/15m 5318.5 5318.2 5318.2 H/s max 5319.4 H/s
[2019-10-06 13:22:10] accepted (55/2) diff 150000 (72 ms)
[2019-10-06 13:23:05] speed 10s/60s/15m 5318.5 5318.5 5318.3 H/s max 5319.4 H/s
[2019-10-06 13:23:13] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348171
[2019-10-06 13:24:00] accepted (56/2) diff 150000 (57 ms)
[2019-10-06 13:24:03] accepted (57/2) diff 150000 (67 ms)
[2019-10-06 13:24:05] speed 10s/60s/15m 5318.4 5318.3 5318.3 H/s max 5319.4 H/s
[2019-10-06 13:24:08] accepted (58/2) diff 150000 (69 ms)
[2019-10-06 13:24:33] accepted (59/2) diff 150000 (66 ms)
[2019-10-06 13:25:05] speed 10s/60s/15m 5318.3 5318.2 5318.2 H/s max 5319.4 H/s
[2019-10-06 13:25:15] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348171
[2019-10-06 13:25:39] accepted (60/2) diff 150000 (71 ms)
[2019-10-06 13:26:05] speed 10s/60s/15m 5319.0 5318.2 5318.2 H/s max 5319.4 H/s
[2019-10-06 13:26:17] accepted (61/2) diff 150000 (71 ms)
[2019-10-06 13:26:41] accepted (62/2) diff 150000 (65 ms)
[2019-10-06 13:27:05] speed 10s/60s/15m 5318.4 5318.2 5318.2 H/s max 5319.4 H/s
[2019-10-06 13:27:15] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348171
[2019-10-06 13:27:43] accepted (63/2) diff 150000 (61 ms)
[2019-10-06 13:27:54] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348172
[2019-10-06 13:28:05] speed 10s/60s/15m 5318.7 5318.3 5318.2 H/s max 5319.4 H/s
[2019-10-06 13:28:24] accepted (64/2) diff 150000 (61 ms)
[2019-10-06 13:28:27] accepted (65/2) diff 150000 (59 ms)
[2019-10-06 13:28:47] accepted (66/2) diff 150000 (70 ms)
[2019-10-06 13:29:05] speed 10s/60s/15m 5318.8 5318.4 5318.2 H/s max 5319.4 H/s
[2019-10-06 13:29:31] accepted (67/2) diff 150000 (74 ms)
[2019-10-06 13:29:55] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348172
[2019-10-06 13:29:57] accepted (68/2) diff 150000 (68 ms)
[2019-10-06 13:30:05] speed 10s/60s/15m 5318.2 5318.2 5318.2 H/s max 5319.4 H/s
[2019-10-06 13:31:05] speed 10s/60s/15m 5318.2 5318.2 5318.2 H/s max 5319.4 H/s
[2019-10-06 13:31:18] accepted (69/2) diff 150000 (71 ms)
[2019-10-06 13:31:22] accepted (70/2) diff 150000 (68 ms)
[2019-10-06 13:31:28] accepted (71/2) diff 150000 (68 ms)
[2019-10-06 13:31:36] accepted (72/2) diff 150000 (51 ms)
[2019-10-06 13:31:57] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348172
[2019-10-06 13:32:05] speed 10s/60s/15m 5318.9 5318.3 5318.2 H/s max 5319.4 H/s
[2019-10-06 13:32:14] accepted (73/2) diff 150000 (77 ms)
[2019-10-06 13:33:05] speed 10s/60s/15m 5317.8 5318.4 5318.2 H/s max 5319.4 H/s
[2019-10-06 13:33:30] accepted (74/2) diff 150000 (78 ms)
[2019-10-06 13:33:57] new job from pool.bloc.hashvault.pro:6666 diff 150000 algo cn-heavy/xhv height 348172
**[2019-10-06 13:33:59] rejected (74/3) diff 150000 "Low difficulty share" (73 ms)**
[2019-10-06 13:34:00] accepted (75/3) diff 150000 (61 ms)
[2019-10-06 13:34:05] speed 10s/60s/15m 5318.3 5318.2 5318.3 H/s max 5319.4 H/s
[2019-10-06 13:34:30] accepted (76/3) diff 150000 (72 ms)