Microphone and speakers are not working after breakout session

More and more, after I was in a breakout session, nobody can hear me and when someone is talking I can´t hear them. I have to leave the meeting and come back, than it works again. But sometimes if I am in a breakout session, there is the same problem like in the main room. 

I can fix the problem when I chose other speaker on the pc, but this is not working with the micro.

I use a Mac mini in combination with studio display. Sonoma 14.1.2. Zoom 5.6.12.

Thanks in advanced for help.