Missing Touch ID

Bought an M1 iMac a few months back and Touch ID stopped working this week.

Decided to delete my fingerprint and add it again by going into Touch ID in System preferences but on first attempt the +Fingerprint symbol was non responsive.

When I went to try it a second time the Touch ID had disappeared from System preferences and I can't seem to restore it our locate it using spotlight.

No idea how to get it back?

Peter.