Effect Masks sometimes produce Glitches
so this is an issue I've run into for some time now. Every once in a while, effect masks produce glitches on the image. So in this example, I'm using the blue mask as a mask reference on a Curves effect. The first image shows my layer with the Curves effect turned off, the second image with the Curves effect turned on. You see that glitches appear on the layer. This issue is really hard to reproduce as it just occurs very infrequently. But when it does, there seems to be no way to get it to work anymore. The layer seems to be "damaged" and applying a fresh effect and adding the mask to it produces the same issue.
In this example, it occurred on a 3D layer. Not sure whether it were 3D layers the last times this happened.
I'm using AE 22.1.1 on Windows 10, running AE in English while the OS is German if that's relevant. (But it also happened to me on older AE versions.)