For a while I had a guess that issue could be caused by having a "-" sign inside the subdomain, like "web-app.baraboo.app" yet I tried the same with the "solid" subdomain name and it also does not work.

Metadata page in TestFlight for my latest bundle says domain "com.baraboo.app" is available (there is a green check mark against it). Yet the same message.

Is there any reference that .address command does not work? Is there any workaround possible?

That is sad! Does anyone have an official reference that .address is not supported? What is about higher iOS versions? Any workaround - as sending raw commands?