There are a couple of issues that commonly occur with the XP-Pen tablet drivers. First is the screen flickering. If your screen flickers on and off, it is most likely happening because the refresh rate of the XP-Pen tablet was incorrectly detected at 59Hz. You need to adjust the refresh rate to be 60Hz. Search for Display Settings, open the app and select your XP-Pen monitor then click the Display Adapter Properties link and use the drop down under the monitor tab to select 60Hz.
The other common problem with XP-Pen and other drawing monitors is a loss of pressure sensitivity during long drawing sessions. I’ve had luck in stopping the drop-outs by adjusting the Windows Ink driver settings. Search for Pen Settings and open the app. Disable all of the switches and select Nothing in all of the drop downs. This will keep Windows from interfering with the drivers that control your pen. Your mileage may vary.