Layer mask cycles through modes when moved

If I select a mask on a layer by double clicking it, then try and move the mask with my mouse the mode of the mask cycles through each option (Add, Subtract, Intersect etc.) until the mouse is released. If I move the mask with the arrow keys on the keyboard it does not do this.

I am not using a tablet and have not noticed this before. I am on Windows 11 Pro 24H2 build 26100.3194
using after effects 25.1.0 build 68

I have uploaded a video starting off with an empty project to show that this is repeatable.