miner_hashrate and worker_count show zero whereas logs show non-zero
Hello
First of all, thanks for your job.
Trying monero-pool with 2 accounts and 7 workers
Could you explain : 
Logs show (right) : 
2021-06-09 06:36:11 INFO  src/pool.c:3822: Pool accounts: 2, workers: 7, hashrate: 34390

But API (http://@IP:4243/stats) says :
pool_hashrate | 33756
round_hashes | 1616602794
network_hashrate | 2630707752
network_difficulty | 315684930345
network_height | 2379246
last_template_fetched | 1623220236
last_block_found | 0
pool_blocks_found | 0
payment_threshold | 0.05
pool_fee | 0.01
pool_port | 4242
pool_ssl_port | 0
allow_self_select | 1
connected_miners | 2
miner_hashrate | 0
miner_hashrate_stats
0 | 0
1 | 0
2 | 0
3 | 0
4 | 0
5 | 0
miner_balance | 0
worker_count | 0

So why miner_hashrate is zero, so are worker_count in API ?
Thanks
