Hello, for some time Firefox draws only an outline of a window when I try to open "Help" sub-menu ( or any other firefox sub-menu), or uBlock Origin and Video Download Helper menus. Additionally after I try to open any of the sub-menus even the main Firefox menu draws only an outline. Firefox behaves like this until program restart. After it's opened once again the main menu is accessible (but not uBlock and VDH menus). The other way is to open a private window and access the main menu there ( but only the main menu as in "regular" window). I tried to uninstall the add-ons and clear all the config files but no luck there. Besides, Firefox menu behaving strangely on its own indicates that it may not be any add-on's fault. I attach the screenshot. It was not easy to capture what I'm talking about because the outline usually disappears after pressing "Print Screen". Please help.