Not sure this is definitely the same issue but I found this thread while looking for any insight into why my trackpad might be having problems... thought about it, and said problems did start right after the 12.1 update... so, for whatever it's worth: I'm using a mid-2015 MacBook Pro 15", so quite a bit older than the other models mentioned in this thread (that said, it has no other issues). The problem seems to mainly afflict the center region of the built-in trackpad, though it's not always super consistent (as far as I've discerned, anyway). Tap to click simply will not work in the center, no matter how many times I try it. If I use the perimeter of the trackpad exclusively, it seems fine. Mixed results with two-finger-tap secondary clicks. Motions that cross larger portions of the trackpad seem to be hit or miss; frequently, single-finger movement started at the perimeter may continue into the center smoothly but in other instances it sort of skips a bit in the middle and picks up at the perimeter again. I've checked everything available in System Preferences. And it's been on the "Light" sensitivity all throughout. The whole thing has been driving me crazy. I just installed the 12.2 beta update to see if that might help; unfortunately, it has not.