For testing I have setup a new stream in the encoder for Opus.
First I figured out that, that there are no meta data transfered to Icecast.
Now have recognized, that I got short interruptions in the streams. In the Opus stream there were more and longer interruptions as for the MP3-streams.
The interruptions happend a few in an hour. For the Opus stream more and sometimes also a few in a row and also for longer time than for the MP3 streams.
So I got a feeling that the reason for that could be the Opus stream. So I disabled the Opus stream and I haven’t recognized any interruptions in the streams since more than 3 hours.
So I am quite sure, that the Opus stream was the problem. The CPU power is now only between 6-9%. With the Opus stream it was about 50% higher. But anyway, the CPU power should be not the problem, I think!
@UliNobbe I have missing a category error.