Are you sure it is not the cable that is the issue, or are you saying you tried 3 different displayport cables? Where are you plugging in the displayport cable on the pc? Make sure you have cleared any dust in the cables or in the socket for the plug in the monitor.
The monitor could be the issue but it is better to check for other problems first.
I tried another cable and still got the same result. The gpu has different slots for DisplayPort and I tried all 3. I don’t think it’s dust since everything is brand new and they had their dust protectors on.