AU host crashes in IOThread in macOS 11 and later

Hi, I've problem with an AU host (based on Audio Toolbox/Core Audio, not AVFoundation) when running on macOS 11 or later and Apple Silicon – it crashes after some operations in GUI. The weird is, it crashes in IOThread. Could this be caused by some inappropriate operation in GUI (eg. outside the main thread) that effects the IOThread? Sounds quite improbable to me. And I did not find anything suspicious in the code.

There are two logs in the debugger:

[AUHostingService Client] connection interrupted.
rt_sender::signal_wait failed: 89

...

And here is the crash log:

...

Thanks,

Tomas