Yes! It's an LG Ultra HD running at 2560x1440 @ 60Hz
Same monitor here. Damn strange. I'd experiment more if I didn't need to work with it. Keeping the monitor off for awhile seemed to help , but a quick off/on didn't.
Yup, I turned it off, disconnected it from my Mac and left it for a minute, then rebooted. All seems fine now.