I have a issue with "br0". Everytime when I restart my unRAID Server and want to start the docker containers I'll get an error. I checked the log file but I can't find anything. Also I checked the container and if I check "Network Type" I can't choice "custom br0" it's gone. The solution to make it working again is going to the setting page the the Docker tab and disable and enable Docker. Now everything is returned to the normal situation. If I check the Docker container "Network type" is now "custom br0".
I think I reported this before. So I think it's a bug whats exists for a longer time period.