[BUG] Accessories get re-added on every Homebridge start
**Describe the bug**
I have some automations that trigger the General Mute Switch in HomeKit. Today I noticed that this switch gets removed from my automations on ever restart of Homebridge. Therefore my automations show no devices configured in the Home app. The only thing I changed lately was activating the publishAllTVAsExternalAccessory and therefore deleting the cache. After that I deactivated the clean cache option again. The log shows on every restart of homebridge that it’s creating all devices/activities. 
I‘m running all the latest versions (iOS, homebridge, plugin)

I can reproduce the behavior when disabling the publishAllTVAsExternalAccessory and running the plugin in bridge mode. Then everything works as expected again and my automations keep the way they should. 

**Expected behavior**
The automations with Harmony devices shouldn’t change on the restart of Homebridge. 

**IOS (please complete the following information):**
- Version 14.1
- Device: iPhone 11 Pro

**Config**

"name": "MirkoHarmonyHub",
            "hubIP": "192.168.99.13",
            "publishAllTVAsExternalAccessory": true,
            "mainActivity": "Entertain",
            "publishGeneralMuteSwitch": true,
            "publishGeneralVolumeSlider": true,
            "publishGeneralVolumeSwitches": false,
            "linkVolumeControlToTV": true,
            "showCommandsAtStartup": false,
            "platform": "HarmonyHubWebSocket"
