Rectangles appearing when drawing under a layer

I have this file in which a normal layer in "color" mode on top creates the sepia tone. Recently, when I modify any layer below that color layer, rectangle artifacts like this appear. This also happens when modifying the text, and if I shift the mode of the layer to anything else that "modifies the color of what's below" (soft light, etc...)
If I disable the "top" layer, I can edit text and draw fine without such artifacts forming.
Artifacts don't stay forever, as they clearly disappear when photoshop does a redraw/refresh. But they are a nuisance for my work. Please look into this bug. Thank you.
