Unable to use Apple Watch to authorise System Pref changes

[piattj]

I routinely, and successfully, use my Apple Watch 6 to unlock my M1 Macbook Air but cannot use it (double clicking on Watch) to authorise System Preferences changes. When I (eg) go into Security & Privacy then click the lock to enable changes, I am asked for admin username/password, whereas I want to be able to authorise using my Apple Watch.
I actually also have another Macbook - a MacBook Pro, also running Big Sur - and on that machine I CAN use my Apple Watch to perform that action... WHat might be the problem? Why can't I do this on my Macbook Air?

 

[mystery hill]

In Security & Privacy preferences, deselect ”Use your Apple Watch to unlock apps and your Mac”, then restart your Mac and turn this setting back on.

 

[piattj]

In Security & Privacy preferences, deselect ”Use your Apple Watch to unlock apps and your Mac”, then restart your Mac and turn this setting back on.

Doesn't seem to have done anything. Still the same... still asking for password

 

[piattj]

OK all clear now. I missed the obvious step in that the user requesting authorisation via Apple Watch must be an Admin, nor Standard, user...

 

[mystery hill]

👍