Installed BaReinhard's repo and rebooted. I was able to connect to the AirPods when it launched back up and for a brief moment sound actually came through from youtube on the AirPods and I thought I may have fixed it, but then it cut out again after about two seconds. I'm getting the feeling that it connects and then gets disconnected almost immediately for some reason. Indeed, looking at bluetoothctl it seems to connect then disconnect to the devices immediately.
Thanks for providing the log file. I don't notice anything different between the 2 runs, so it's not something related to a configuration.
Try removing pulseaudio completely then reboot the system, this might get rid of any PA interference.
The finally solution for me was manage the relationship 1:1, one speaker with one dongle (USB). For spread the sound on all speaker i used an virtual audio card with "paprefs". Maybe we'll see this skills on new Bluetooth versions.