Well it does not look like you have an HDMI connection on your video card or else I would have told you to try that. I have had an issue before using displayport on my old Samsung monitor where it would stop recognizing the source or whatever, but when I switched to HDMI, it fixed the problem with connection issue. However something that used to fix my issue with displayport was if the error occurs, just unplug the AC plug from the back of the monitor wait 5 seconds and plug it back in and see if that works. Hope you find a permanent solution.
if not, just contact AOC support.