Show all updates Big Sur 11.6

The current version of Big Sur is 11.6.5

A 2017 Mac Mini can also be upgraded to the latest version of Monterey: How to upgrade to macOS Monterey - Apple Support

Are All of these setting in the Software Update Applet enable on your computer ?

If they are all Enable and the computer has not offered updates past Big Sur 11.6 - what other software is installed that would stop the updates to be offered ?

> Mac Mini 2017

?? AFAIK there are Mac mini late 2014 - Mac mini 2018 so that does not compute ??

Anyway, do you have any nasty 3rd party stuff (virus apps, "cleaners", VPN etc) that might intervene the Mac seeing updates?

If yes, uninstall them and try again (or maybe try in safe-mode).

> Maybe the user purchased a Mac Mini 2014 in 2017 ?

Yes, some users refer Mac mini 2018 as "Mac mini 2020" as it was advertised like that in some places although that really refers to the Mac mini 2020 M1.

Maybe the user purchased a Mac Mini 2014 in 2017 ?