Finder oddity with my M2 Pro MacMini

Ive had this mini for about 8 months now It’s running Sequoia 15.8.1

I wanted to add a folder to the side bar, something I’ve done on all the Macs I’ve ever owned. (I’m writing this on a Tahoe MacBook and it’s fine on here)

The Mini will not let me.

Any thoughts?

Are you using the drag-and-drop method or the Command-Control-T method for adding the folder to the Favorites section of the Sidebar? Is there anything you have selected in Finder>Preferences>Sidebar in Tahoe that is not selected in Sequoia?

just drag-and-drop as i have done since time.

I am running Sequoia 15.8.1 and the drag-and-drop method for placing a folder in the sidebar works for me.

Have you restarted the Mac Mini? How about a Safe Boot to clear caches?