HomePod mini stereo woes (two issues)

CaprDeemo, regarding your main issue, I can confirm it is happening with me too. I have the same setup (all over my LAN WIFI). I have never used Airplay from my MBA M1 (Monterey 12.2) to my stereo paired HomePod Minis (15.3). I always use bluetooth (without issue).

My detailed testing protocol:

I changed the MBA Audio Out settings to HomePod Mini. FIRST Test: music played for about 2 minutes then the audio completely stopped. Right away I went to the Audio Out settings. It has auto switched back to the MBA internal speakers. Also, there were now two listed HomePod Mini Audio Out options (in my setup the HomePods are named "Living Room"). I went ahead and tried selecting one HomePod Mini Audio Out option then tried selecting the other. Both times it gave a can't connect message. But a few seconds later the listed Audio Out options went back to listing just a single HomePod Mini. SECOND Test: I selected the HomePod Mini option and the audio was back playing perfectly right away on both HomePod Minis. About 14 minutes elapsed when no audio was coming from the HomePod Minis. I double checked that Music had not paused and it had not. By the time I had done this check -- less than a minute -- the audio began playing properly on the HomePod Minis. FINAL: Test I continued to let the music play from the HomePod Minis. It played perfectly for about 6 or 7 minutes then completely stopped. This time, like the first test, the Audio out auto connected back to MBA internal speakers. I right away went into Audio Out settings and saw that again there was two HomePod Minis now listed (Living Room in my HomePods). I quickly screenshot it and have added it to this post. Hopefully it helps.

You can tell Apple Support it seems likely this is a bug. I'm not going to open a case as I just do not use Airplay from my Mac to the HomePod Minis. But nice to know Apple is aware and will be working on a fix all the same.

Sounds like a wifi issue (especially the 20 minute delay before the problem occurs).

Here are some things to try (from a collection of tips I have gathered):

Your router might be "too smart" for the Homepods that don't seem to be able to keep up with wifi optimising strategies. Try changing them to static IP addresses via your router settings. That made my system more reliable (but not perfect). + The original Homepod also seems to suffer from wifi problems related to "smart" routers/modem. Solutions included temporarily disabling the 5GHz band (to trouble shoot) and assigning a static (fixed) IP address. These are router settings and every router seems to have a different method of changing settings. As a start try typing 192.168.0.1 into your browser address field. This should load your router set-up page. The default user name is usually admin. If you are lucky there will be a help page for further steps such as enabling/disabling "smart connect".

Since the update to 15.3 we have had a few stereo issues also but for when the audio has been off for a while. When I start music up it take 10 seconds or so for the other HomePod mini to begin playing along with the other one.

Captdeemo, I had unplugged my HomePod minis for about an hour due to needing to do some house cleaning :-).. So I tried the test again (M1 MBA Airplay to HomePod mini Stereo pair) this evening. The Audio is still cutting out for me too. What I showed in my troubleshooting screenshot (in my previous reply) is still happening too: the HomePod Minis will show up as 2 separate Audio out destination options during the audio stoppages. When one of the Audio Out options disappears (after about 30 seconds) and back to just one Audio Out option for the Mini stereo pair, that audio starts to work properly again.

Hopefully config changes or other changes can make it work, however, I think this is heavily leaning toward being a bug. You have opened a ticket with Apple Support, and Apple Support is on these forums. They are aware of the conditions to replicate the issue. I suspect this will have to be addressed in an OS maintenance release. In the interim I'd suggest using bluetooth as the workaround. I use only bluetooth and it has no issues.

This is often the best way to fix a smart home device glitch. Was same with Echo devices. Just remove them, then add them back. Update too if needed.