Issue when using Go2RTC with Dahua cameras #5317

If you begin viewing a stream from a Dahua camera on the "Watch" page using the Go2RTC player, the camera stops sending ONVIF events, which prevents alarm-triggered recordings from taking place.
This issue does not occur when using any other players.
The situation can be resolved by applying an additional configuration setting for the camera.
The stream connection string typically looks like this:
rtsp://XXX:XXX@172.16.27.88:554/cam/realmonitor?channel=1&subtype=0&unicast=true&proto=Onvif
To fix the problem, you need to append a parameter specific to Go2RTC—#backchannel=0—to the end of the string.
Consequently, the entry in the Go2RTC.yaml configuration file should look like this:
rtsp://XXX:XXX@172.16.27.88:554/cam/realmonitor?channel=1&subtype=0&unicast=true&proto=Onvif#backchannel=0
The #backchannel=0 suffix should likely be added for monitors where the Device Class=Camera.
I have never used Device Class=Speaker, but I assume it is intended for transmitting audio from an operator to the monitor.

This issue was originally identified here: #5305 (comment)

@connortechnology
Are you using Dahua cameras?