So I had dropped the battery side of this contact sensor and it performed a perfect belly flop on the hard bathroom floor. I picked it up and it seemed to be broken, the magnet didn’t feel as strong anymore and it started to only register the open state. I did a lot of playing around with it and found that it had somehow become offset. It will only register as closed in this specific position:
It’s definitely not working as it was before I dropped it, but it’s not completely broken! Saw a lot of people posting with this problem and thought this info could come in useful for someone out there!