Perhaps a factory reset, or perhaps using the Samsung cable supplied with the monitor (Samsung does insist on this).
Or perhaps doing some due diligence before using some 3rd party overlay or another to make sure it will actually work as intended, on the 3rd party's website.
You never know, someone there may have already have found a solution (or not) to a problem that doesn't seem to exist to the non 'ah but' users that genuinely try and help people that go into hissy fits because they want to do something that is not part of their original question and only comes up once you have failed to solve an unmentioned issue for them because they didn't erm, mention it in the first place, which would have elicited much more helpful and precise suggestions of solutions from much more knowledgeable forumites with specific experience of the issue.
Or perhaps not.
I give up.
