Re: U2518D, firmware M2T103, stuck
After I shutdown my PC, monitor turned off (black screen) with light in power button. After I started my PC, monitor stayed black. Tried using HDMI instead of DP, nothing changed. I powered off monitor for 5 minutes then plug it back in and it was still black without any button working. I plugged my old monitor that works back in. I found log file in log folder hope it helps in debugging problem.
Log file: https://pastebin.com/qFkEWMgJ