I'm also having this problem. Spotlight can find applications, but not files and folders. I can't search inside Apple apps incl. Notes, Reminders, and System Settings. Finder search works. Also, when I search for apps, I sometimes get web results and the "Search in Finder" option as well. And sometimes, the icons are kind of epileptic flashing between the app icon and a grey box.

Still not working after the 14.1 update. The terminal commands are really cumbersome. I suppose there's probably a way to automate, or maybe I could just use the local account only, but I'm being stubborn. I want to see a fix!

For some inexplicable reason, Spotlight has been working for me over the past few days. I'd been doing the whole su/mdutil series until then.

This seems to have resolved for me after upgrading to 14.1.1. Anyone else?

New fix: Toggle FileVault off and back on (or vice versa). For whatever reason, this seems to fix the Secure Token issue and seems to last weeks, if not months.