I have reworked the Sonos support in PR #12126. No new features are present but it should be more responsive, especially with grouped players.
The update should also be more robust and not log any warnings.
It is a huge rework and I probably have introduced new errors. So if you want to help out with testing, just copy my sonos.py to your config/custom_components/media_player/
folder (and restart Home Assistant).