I recently moved and this started to happen on my Ultimaker 3. Prior to moving I use to always print over ethernet. In my new office I setup to print over Wi-Fi. Printing over Wi-Fi causes this problem both for the screen glitch and the random pauses during printing. Within seconds of the print head centering and preparing to print over Wi-Fi the screen glitches. After taking things apart and cleaning, performing a factory reset, uploading firmware again, the problem persisted. On a hunch after reading this thread that it might be tied to printing over Wi-Fi, I attempted to print from a USB stick with success. So the issue appears to be tied to enabling Wi-Fi.