Hi! I’m running Ubuntu 22.01 LTS on my Framework and my fingerprint scanner is working fine.
Are you perhaps dual-booting between Ubuntu and Windows (or another OS) on the same SSD? In my experience, it seems like if I boot two or more OSs from the internal SSD, only one OS gets to “own” the fingerprint scanner, and the other OS can’t access it.
On my Framework I have Windows booting from the SSD and Ubuntu booting from a 256GB expansion card. Fingerprint authentication works fine on both OSs.