I've recently developed a new bad habit. When I play my pick starts to slide towards the bottom of my thumb. I've never had this problem before. I always hold it at somewhere in the top crease of my thumb, but lately it's been sliding down below and I can't really help it unless I stop and go out of my way to push it back.

Just wondering if anyone has had this issue, and what did they did fix it. Obviously it's gonna take awhile to get used to keeping track of the pick in my head, and it's gonna get obnoxious like any other bad habit, but I'm looking for people who have had this same problem and what they did to solve it.

Any help is greatly appreciated. Thanks.
maybe the sweat from the thumb made it quite slippery.. also depends on the pick material.