I noticed that if you hit escape instead of right clicking to stop drawing with the free form line tool it’ll undo whatever you did directly before making the line instead of undoing the line it’s self and some times the line will just get stuck on the screen until you erase it by hand. It also seems too cause some weird glitches when there’s a layer with reduced opacity under it. It makes parts of the drawing under the line highlight and disappear even if the layer under it is locked. I had it completely bug out on me last night and erase half my drawing. undo didn’t restore the part that was erased.
Right clicking with the freeform line tool seems too work fine though. I just thought I should report this since I noticed it.