First, this is a user-to-user forum and Adobe's presence is severely lacking.
Second, I have never seen this happen on a PC. Could it be your video driver needs updating?
Last, if you want Adobe's help on this, file a bug report or contact TS.
Thanks for your response, Harm.
Using a Mac, my video card driver is current as long as I have the latest OS updates installed - and I do.
What exactly is TS and how do I get there to report a problem?
TS = Technical Support. Go to the Adobe website your your country and look for the TS contact number and give them a ring.
The issue occurs only with projects with the preset of HQ 1920x1080p.
at a 720p project setting, clips (whether 1280x720p or 1920x1080p) are displayed normally in the program monitor.