Hi Heiner, and thanks!
I’ve got no other active plugins that involve Airplay (as far as I can tell).
Here’s perhaps another clue…
After having to scratch rebuild my Rpi, I’ve got a clean and up to date installation of M2P and LMS. On that clean installation, I added the ShareTunes2 (Fork) (v0.102.2) plugin (per the instructions on M2P). I am running the „Starter“ setup on the HiFiBerry page. My name for this player is „kitchen“.
With this installation instead of „kitchen“, I saw „kitchen #2“ show up on my Airtunes list. Selecting „kitchen #2“ and playing audio resulted in no sound.
So I rebooted the Rpi (and therefore M2P and LMS). Now, neither „kitchen“ nor „kitchen #2“ show up in Airplay.
Interestingly, a second player in my network called „Livingroom“, (with the same configuration but without the ShareTunes2 plugin), still shows up in my Airplay list, but as „Livingroom #2“.
Thank you so much!