Watch Series 9 Siri asks "Which room?" after Watch OS 26.x update

Siri problem on Series 9 Apple watch after 'upgrading' to Watch OS 26, now on 26.2

When running Watch OS 18.x, I was able to ask Siri to turn my den light on (or off) and the light would turn on (or off) without any problem. However, under Watch OS 26.x, when I ask Siri to turn the den light on, she asks "Which room?" and presents a list of rooms on my watch face and I then have to 'tap' the appropriate room in order for the command to complete.

The same 'den light on' command works correctly when using Siri from my iPhone 16 Pro Max running iOS 26.3 I.e. the den light turns on without my having to do anything else.

Is there a fix for this 'bug'?