Multiroom Mode Player State Errors

I am running Volumio 3.785 on multiple RPi 4, all on a hard wired network to be able to use Multiroom, but I am having problems with certain streams (particularly BBC Radio 6 Music) and Volumio losing track of what it is doing.

From a reboot, everything is initially OK. I can add the remote nodes on the master.
When I select the stream everything plays OK on all the nodes.
The master node status changes to playing as seen by the triangle play button changing to the square stop button. The master node also uses the AmpControl plugin to turn the amp on/off which follows the player state.

If I then stop playback on the master node, the play button changes back to the triangle, all audio stops and the amp turns off. So far so good.

Now if I try and start playback again (either by reselecting the stream or hitting the play button), I get audio from all nodes, but the master remains showing the triangle play button and the amp does not turn on.

At this point I’m stuck and can’t stop playback as the player screen thinks it’s still in stop mode despite audio coming out of all the nodes.

If I select a different source, then sometimes the state will change correctly, but anytime I select the original stream I am back to the same state of the status being wrong.

The only ways I have found to recover from this is either rebooting, or removing all the remote nodes from the master, neither of which is really a valid work around.

Any ideas of how to resolve this?

Thanks,
Simon