AppleTV 4K remote - volume up button 'stuck'.

Suddenly happened last night, AppleTV 4K remote started turning volume up to maximum.

It's connected to a Sony TV with Sonos sound system attached to that.

Had been working no problem until this seemingly spontaneously started.

Have had to remove the remote from the room before it blew speakers!

Thought it may be low on charge so charged it overnight in another room but still doing it.

Any suggestions?

Seems to be an occasional issue as have found a lot of other threads reporting similar issues with no real advice on a fix.