I used to have a 1080p TV set up as a second monitor with hdmi. I recently bought a new 4k tv (sony x85j), but when I connect it to my gpu with hdmi the option to change resolution is greyed out in windows and it defaults to 720p. All I did was unplug the hdmi cable that was in the old tv and put it in the new one. Applications I launch within windows can be set to 4k and it works fine. But for some reason I can't change the resolution in windows itself. I tried plugging it in to a different input on the TV but didn't have any luck with that. I haven't tried changing the GPU (rtx 3070) input yet though. I have a new HDMI cable coming in the mail that I hope will resolve the issue, but I'm beginning to think that may not work because the TV seems to handle 4K resolution fine if it's a windows app. I am considering uninstalling and reinstalling my GPU driver, but I have put this off for now until I test the new HDMI cable. I've had weird issues with my second monitor before and only want to mess with the drivers as a last resort. Any recommendations are greatly appreciated.