G-sync only working sometimes

[heyheyhey]

Hello! I recently got a new monitor and was hoping some of you who are more tech savy could help me out. I've looked online a lot for an answer to my problem, but haven't been able to find anything that works.

I recently got an off-brand monitor for cheap from newegg. It's a KUU MH270UG 4k monitor with a refresh rate of 60hz. I use the 4k 60hz for movies and non-competitive games, but when I play games like Overwatch I set it to its 1440p 144hz setting. The monitor is a freesync model, so it's not necessarily supposed to work with g-sync, but it does work every time when I use it in 4k 60hz.

The problem I'm facing, though, is when I use the 1440p 144hz setting. Sometimes it will work without error, but most of the time my monitor will turn black and say "Not Supported" and I will have to disable g-sync. The odd part is that I don't change any settings on my end to make it work, it just works randomly sometimes. This holds true even for the same game. For example, sometimes it works when I play Overwatch, sometimes it doesn't when I play Overwatch, even though I'm making 0 settings changes - it seems random.

I tried looking online for awhile to see if anyone had a problem like this, but I haven't come across this specific issue. In case it's relevant, my monitor has a 1.2 DP port and 1.2 DP cable hooked up to it. Any help would be appreciated - TY!