Monitor/TV driver unstable, keeps reconnecting periodically after switching display to 4k/144hz

For months I was suffering from an issue that caused the signal to my TV from my PC to intermittently drop, or flicker with green glitches etc.

After months of troubleshooting (DDU, different cables, CRU etc) I realised I never tried uninstalling the driver for my TV. I uninstalled "Generic Monitor" driver in devices, and restarted my PC.

Like magic the problem disappeared and stayed gone for 2 months, but at the time I applied the fix my signal was set to 1440p/119hz, even though my TV is capable of 4K/144hz.

I decided to try and set the display settings to match this, but then the problem returned in full force, and now no matter what I do it persists, even after returning to 1440/119 and uninstalling the driver over and over.

Can anyone help me make sense of this? It's driving me crazy.

Also, I should say, *usually* the issue only starts after 15-20 minutes of the PC being on from a fresh boot, and becomes more unstable as the goes on. But then other times it starts happening from the very start.