This has been going on for a number of years, at least since the Minis could be stereo paired anyway. I got mine just as that was being introduced.
In my case I regularly had one speaker (the RH one) disconnect from the stereo pair after a short time of playing anything on the TV (not music though, it only affected movies etc.). It would cut in and out during the time it was playing.
I have seen, and contributed to a few threads on the matter over that time, which I can't find now.
However, there have been many suggestions to fix it, or at least 'workaround' the issue.
I was never convinced by the Private WiFi Address address trick. I thought it would work for a while, then the same issue would eventually crop up again. That's a device specific setting anyway, it's not even available on a desktop device.
I also tried many other tricks, restarts, resets, reinstalls and so on. Until I got to a fully manual IP address setup, and private stuff disabled, and still the issue kept cropping up. I tried all the known suggestions I could find.
Eventually It would remain stable for a while, after a few sets and restarts could be a few weeks if I was lucky. But it was never clear what actually sorted it at any time.
Then iOS 17 came about, and after that I have everything reset back to defaults, my DHCP server is auto, Private WiFi Address is enabled on my iPhone and iPad. Although I do use CloudFlare (1.1.1.1) for my DNS settings.
Since its release last year I haven't (yet!) had a single drop out.
That would suggest to me that we have just been fighting a bug all this time, and it might be that Apple have finally fixed it. It's certainly not unknown for possible bugs to suddenly disappear after an update (it used to happen a lot after supposed 'security' updates).
Anyway, that's just in my own experience here. Perhaps try just resetting everything back to default, and start afresh there. YMMV applies as always :-).
Cheers.