How to unhide a person iOS 17

I am trying to add person A in Photos -> People & Pets (running iOS 17.3.1), but that person doesn’t appear in the list. Even when I swipe up on a photo of person A with another person in it - it finds person B but not person A.

I’ve read a bunch of posts saying to simply unhide the person but there’s no functionality for that as far as I can see. I’ve also tried on iPad and Mac on latest versions of both of those.

I’ve even reset all the faces and had it redetect everyone. I think I must have hidden this person’s face and somehow Apple isn’t letting me unhide it.

Any help is appreciated!