Invisalign loose over back right molar

I just changed into a new tray (6/14), and the tray fits everywhere except it’s a little loose over my very last back right molar. When I bite down, I can feel the tray move and it pops up slightly (but still on my tooth). I’ve tried chewies but it almost feels as though the tray is too wide for my tooth. I’ve worn my last tray more than 22 hours a day, and it fit perfectly right before I switched to the new tray. There’s also very minimal gapping in my new tray, which I suspect will go away soon.

Thoughts on what the issue is?

Thank you!