I'm kind of a newbie to the grease pencil tool, and while trying the different brushes I've noticed after a while that any line I draw is a bit darker, thicker and more opaque but then go back to their normal material look when I lift the stylus from the line. It's really annoying and I can't seem to find what could be the parameter for this, but I've noticed it won't do this on a new file. I've already tried to copy and paste my drawing in a new file, but the grease pencils material are linked to the strokes and it won't change anything.
If anyone knows how to fix this, I'll be grateful.