About a few weeks ago, I began experiencing random graphical glitches and artifacts.
My taskbar or other apps (such as Libreoffice) would get random patches of black, where I would have to mouse over in order to partially fix.
Sometimes when scrolling, the previous frame would remain (think dragging a Windows window when the computer is lagging) and I would again have to mouse over to update.
Also recently, Firefox has been experiencing odd moments where it would begin to flash a frame that happened a second ago.
I'm sorry if I can't provide images, as they happen randomly.
System: Lubuntu LTS 16.04 Intel Pentium N4200 (Intel HD 505 iGPU) 4 GB DDR3 RAM Firefox 69.0.1