Didn’t go for the full rig just chose parts from the presets Spine / Arm / Leg / Finger but there are some missing. The Thumb I copied a Finger but doesn’t recognise it ?
could you share the metarig?
Sometimes the Rig Type gets lost. I don’t know why exactly, it may have something with undo.
Anyway select the first bone in the finger, go to Bone tab > Rigify Type and give it a limbs.super_finger type.
That’s my best guess.
I started on the Thumb again, chose the limbs.super_finger template (or can make 3 bones and 1st / root of thumb to same type) but renaming seems to be key so must be thumb.01.L + thumb.02.L + thumb.03.L, which works fine.