vary odd, have you tried changing cable, looks like a DP cable ? is so there have been bugs with some DP cables/displays.
of hand cant remember the details but something to do with the display settings and DP support
(something to do with display being in the wrong DP mode maybe)
can you try changing the cable
and switchresx has been used by some people to fix some resolution bugs
http://www.madrau.com/
^^ thank for posting the screen shot of the display panel, in the past lots of people have made the mistake of not clicking on the scaled option
🙄 and it's an easy fix (im amazed how often it happens)