I have been having this problem for a while now, and was hoping the new update of iOS 15 might solve it, but no dice.
When I finish a phone call using my Air Pod Pros, I have to either restart voiceover, or ask SIRI a question in order to get voiceover working again.
Further, triple pressing the lock button on my 12 mini has to be performed three seperate times to get voiceover to come back, as if the first triple press doesn't really do anything.
It is bizarre.
Surely I am not alone on this one, but I haven't seen this mentioned on site or in the bug updates, which makes me think I am missing something obvious and/or just being dumb.
Any help greatly appreciated, this of course isn't a show stopper, but for sure annoying.