We anticipate resolving this problem in an upcoming release, and I will update this UserVoice item to “Completed” when the new functionality is fully tested and available.
With newer Apple systems, especially those based on the T2 chipset, many previously singular states of the Built-in audio interface are now exposed as completely different virtual devices by MacOS. One used to be able to plug in a pair of headphones and let the OS re-route the output automatically. Now, this either requires a manual change, or utilizing new frameworks for the same functionality.
Thanks for your feedback, and please stay tuned.David Monostori commented
This also applies to the new 16" Macbook Pro.
My 2016 worked fine, this new 16" doesn't.
Also using 3rd party apps like soundsource to route sound has no effect at all.