Why would you enable Airplay “Require password” in the first place? If you do not trust people to use Airplay they should not be on your network - that’s what guest networks are there for.

I cannot believe Sonos would still think there’s a password required when there isn’t anymore, especially after a reboot, but you seem to need a reset. Seems strange indeed……

One of my kids, my wife etc. might have turned it on in the Apple TV or Home app. Not hugely bothered if there’s an Airplay password - so long as it works - unfortunately with Sonos Airplay passwords don’t work and now all speakers seem stuck and won’t accept any password for Airplay.

Just an update after spending an hour on the phone troubleshooting with Sonos support.

The call got escalated to an engineer who immediately responded with:

The solution is to remove each Sonos device from HomeKit and reset each Sonos device in turn before re-adding to the Sonos app.

By 'remove from HomeKit' I assume they mean don't add the Sonos speaker to the Apple Home app - which is a shame because that app lets you do clever stuff like pause the music if you leave the house etc.

They also indicated that it would be best if I don't add my Sonos devices to the Apple Home app in future.

You could also tell your kids and your wife only you are allowed to change the settings on the ATV…..

So remove, factory reset then you can add again to both Sonos and HomeKit, just do not set up the PIN.

I did this a few months ago by mistake. Had to start from scratch on everything. Removed all Sonos from homekit, reset all sonos devices. Took several hours. Surprised to hear they said don’t put Sonos speakers into HomeKit. What is the point of Airplay and home automation in general?   If Sonos keeps pushing in that direction I’m eventually going to junk it and just go all Apple Homepods.

Homekit has had a fault since some time for non-Apple speakers. That could be the reason.