Spacebar/fingerprint detector is coming off Blackberry KeyOne

One side of the spacebar/fingerprint reader on my BlackBerry KeyOne has come loose and it’s flapping up and down. Still works for both typing and unlocking my device, but I fear I don’t have much time left before it falls off. I’m trying to figure out what was keeping it down before, so I can get it back into place—is this one of those scissor-action buttons? Did it snap into place?Was there adhesive? I can’t get a look without pulling it off and I fear I will lose functionality if I do that. It looks like maybe there was sort of a tab/hook keeping the loose side down.