I didn’t test this on a Live-CD 23.04. I just recently upgraded from 22.10 to 23.04. But the symptoms are happening.
There are a few people here as well: [TRACKING] Fn key stops working on PopOS after a while - #27 by Chris_Guidry
This is a 12th gen Framework, purchased last year. I have not run any BIOS update (as it’s still in beta).