Sudden very bizarre display issue in Windows 10. (MSI GS75 to 4K TV)

[Salisryn]

***I have copied and pasted this from my post on another forum in order to try to get a response more quickly, as I'm getting quite frustrated and am considering returning my laptop, but am trying to dissuade myself from making a hasty decisin. My Xbox one isn't having any display issues nor are the apps on my TV. I hope this the acceptable page on the forum to ask for help with this.***

I know it helps to give as much detail as possible with issues like this so I will try to be descriptive as possible.

I often connect my laptop up to my TV to play games or watch something from my couch. Because it's not an HDMI 2.1 supported TV, I sometimes lower the resolution slightly to increase the refresh rate to 120HZ (I can't do this on it's recommended settings) and to increase game performance. This has usually worked fine, except for the fact that I've had issues with HDR looking washed out, but that's on all resolutions.

In order to try to fix this HDR problem, I figured I'd try the simplest solution first, which was to use my Xbone X's HDMI cable to see if my laptop HDMI cable was damaged.

After the usual HDMI cable (HDMI 2) was disconnected and the  Xbox one cable was connected, Windows resized my laptop to 640x480, and it has continued to do this with both cables ever since. Sometimes I can get full screen (by changing the resolution and closing the laptop screen), but it defaults me to a 30HZ refresh rate, or on some resolutions 59HZ. Before this TV would have a default of at least 60HZ at all times. If I attempt to change the refresh rate, windows changes the resolution back down to 640x480, and sometimes even changes the colour output. I've used the Nvidia control panel to see if I can override windows and set the monitor back to what it should be, but either the colour output gets changed and it changes the maximum dynamic range to limited or it simply won't show my TV's refresh rate capabilities in the control panel. It's like it just cannot process the image onto my TV any more, which I dread to think may be indicative of hardware failure (I've only had the laptop for a couple of weeks!)

I've tried everything I can think of, changing HDMI ports, restarting, reinstalling Nvidia Drivers, I've even very frustratingly reinstalled Windows, but to no avail. (Edit: should have said reset Windows, not reinstalled, apologies).

At one point it even start to output display using my built in Intel Graphics, and this was after I reset Windows.

I should point out that the native laptop display seems fine on its own, but simply removing an HDMI cable has really seemed to mess things up with external displays.

(Sorry for pictures instead of screenshots, my laptop still hasn't been set up properly again).
https://drive.google.com/folderview?id= ... FJ1KcxiAb7

Laptop specs:
MSI GS75 with Geforce RTX 2070 with Max-Q Design
Intel Core i7 10750H @ 2.60GHz
16 gigabytes RAM.
1920 x 1080 240HZ (laptop native display).

TV details: 4K UHD Samsung Q70R 55" with maximum refresh rate of 120Hz.

Edit: Additional notes, I connected the laptop up to a standard 60hz 1080p monitor to test that and it worked as it should have with the laptop lid closed. Also worth pointing out my TV is working fine with my Xbox, Prime, and Netflix, so very unlikely to be the fault of my TV.

Edit 2: As a test I tried using a Thunderbolt to HDMI adapter and got the exact same problem.  Very strange and frustrating.