Hello @bluebudgie,
what looks strange to me is the different naming of the monitor which is shown in the screenshots. Normaly this name comes from the monitor itself. And in the first screenshot the data your computer gets from monitor should be right. In the second screenshot your computer gets wrong or no data from your monitor. If you conected the same monitor both times while making the screenshot so your monitor or the cable is the problem.
So I advise to try another calbe first.
The “Do not use RTK” -monitor was yet in town befor: 