So here's something that's been happening when I use a mask on a shape with a gradient applied. If I need to mask something on the shape, I'll switch from black to white (or vice versa) using the X key. When I do this with the mask selected, it resets any gradient applied to a basic black-to-white gradient. Even if I deselect the shape to switch the primary color with X, clicking on the mask will switch the swatches it back. And then again if I switch them, the gradient goes back to being black and white.
Some days it happens, some days it doesn't. Usually when I reboot PS, it stops doing it. Which is why I'm wondering if it is a bug. If that's not the case, what kind of settings gives this result? Thank you for your help!
Could you please try updating your Photoshop version to CC 2017.1.1 and let us know if it helps.
I have updated my PS. It hasn't done it so far, but as mentioned it's an inconsistent bug. I'll comment here if the problem comes back. Crossing my fingers!
Sadly, I just experienced the bug again. Now I'm really wondering if it's not a feature that I'm not aware of. While having the mask selected, I toggled the swatches with X and it slightly altered my gradient (instead of completely changing to a black to white gradient).