Thank you for the advice! Since we are only observing this issue on intel based Macs so far the priority is not that high at the moment. So I suppose you will not hear from me soon. But I will definitely post updates here when we figure out what exactly is causing the issue :-)

That’s the bit I don’t understand here. Local network privacy enforcement shouldn’t vary by architecture. That's exactly something we can't explain either... but we've never observed it on any ARM Mac. Are you using Xcode to build your app? Yes, but we use Xcode from the command line via CMake. Is this UDP work done from your main app? Yes, no additional processes involved Oh, and just because I can’t resist… :D We are hardware manufacturer with a software department ;-) By far the simplest solution here is to implement Bonjour in your accessory. You're right – it's just that this solution was implemented many years ago and has been working perfectly until quite recently...

@Etresoft [quote='815156022, Etresoft, /thread/768782?answerId=815156022#815156022, /profile/Etresoft'] I'm not sure what you mean by "build agent". [/quote] We are providing software running on macOS to our customers (we are in B2B business) and need to support older macOS versions and all the versions up to the current one. So we must be able to build for the old versions in case we need a bugfix. Currently we have several build environments (aka build agents) and are going to organize them better according to our needs. And for that we need a clear statement/documentation from Apple. I'm going to accept your answer to my question since you helped me much more than DTS Engineer (which is actually disappointing...) Thank you so much!