Thanks for your support!
Screenshot from my TV, you see the TV, HDMI1, HDMI2… source inputs.
There is also the Screen Mirroring source, by selecting this input I can eg share my phone screen to the TV.
Attached my full trace log (log.txt).
This is the part where I switched source to Screen Mirroring. It seems that the device is removed during this step:
2022-01-05 15:11:26.198 [TRACE] [internal.service.MainTVServerService] - 10.0.0.78: Received channel: sourceName, command: REFRESH
2022-01-05 15:11:26.292 [TRACE] [internal.service.MainTVServerService] - 10.0.0.78: Value '0' for ID hasn't changed, ignoring update
2022-01-05 15:11:26.294 [TRACE] [internal.service.MainTVServerService] - 10.0.0.78: Value 'TV' for CurrentExternalSource hasn't changed, ignoring update
2022-01-05 15:11:26.297 [TRACE] [nternal.service.MediaRendererService] - 10.0.0.78: Received channel: volume, command: REFRESH
2022-01-05 15:11:26.310 [DEBUG] [tv.internal.handler.SamsungTvHandler] - 10.0.0.78: Device removed: udn=058
2022-01-05 15:11:26.312 [DEBUG] [tv.internal.handler.SamsungTvHandler] - 10.0.0.78: Shutdown all Samsung services
2022-01-05 15:11:26.312 [DEBUG] [nternal.service.MediaRendererService] - 10.0.0.78: onStatusChanged: status=false
2022-01-05 15:11:26.323 [DEBUG] [tv.internal.handler.SamsungTvHandler] - 10.0.0.78: Shutdown all Samsung services
2022-01-05 15:11:26.324 [DEBUG] [tv.internal.handler.SamsungTvHandler] - 10.0.0.78: TV is Offline
2022-01-05 15:11:26.326 [TRACE] [nternal.service.MediaRendererService] - 10.0.0.78: Received channel: mute, command: REFRESH
2022-01-05 15:11:26.328 [DEBUG] [tv.internal.handler.SamsungTvHandler] - 10.0.0.78: TV is Offline
Here I switched back to source TV:
2022-01-05 15:12:13.578 [DEBUG] [tv.internal.handler.SamsungTvHandler] - 10.0.0.78: remoteDeviceAdded: RemoteControlReceiver, http://10.0.0.78:7676/smp_7_, upnpUDN=0eeb58
2022-01-05 15:12:13.580 [DEBUG] [tv.internal.handler.SamsungTvHandler] - 10.0.0.78: Check and create missing services
2022-01-05 15:12:13.582 [DEBUG] [rnal.service.RemoteControllerService] - 10.0.0.78: Creating a Samsung TV RemoteController service: is UPNP:true
2022-01-05 15:12:13.584 [DEBUG] [rnal.protocol.RemoteControllerLegacy] - 10.0.0.78: Open connection to host '10.0.0.78:55000'
2022-01-05 15:12:13.589 [DEBUG] [rnal.protocol.RemoteControllerLegacy] - 10.0.0.78: Connection successfully opened...querying access
2022-01-05 15:12:13.694 [DEBUG] [rnal.protocol.RemoteControllerLegacy] - 10.0.0.78: Access granted
2022-01-05 15:12:13.696 [DEBUG] [tv.internal.handler.SamsungTvHandler] - 10.0.0.78: Started service for: UE40F6500, RemoteControlReceiver (0eeb58)
2022-01-05 15:12:13.699 [DEBUG] [tv.internal.handler.SamsungTvHandler] - 10.0.0.78: TV is online