This is not a general purpose Raspberry Pi forum - it's a RetroPie dedicated forum. If you're having problems configuring your screen then perhaps getting familiar with how the Raspberry Pi (and Linux) work is what you need to do first. If the vendor has some additional configuration scripts used to configure the screen, then try to look up in their documentation how to use those scripts.

@mitu the method is still in config.txt so I guess it refers to Raspi OS as you said.

For the touchscreen it uses a command in the file usr/share/X11/xorg.conf.d/40-libinput.conf

Thank you @mitu

I will have to chase an older model pi. Now I regret not buying the 3b that I saw gathering dust at one shop a couple of months ago.

@stuckinthe90s If Mitu's suggestion to check "in emulator" or "in game" for overriding video mode settings doesnt work, I had a similar problem the other night on a Pi Zero..... i had a message floating across the screen saying something to the effect of the input signal is not compatible. I ran raspi-config and found "Display Options" then "Resolution". When i opened it was set to something in the middle of the list.... I arrowed up to the top of the list and found "Default Monitor preferred resolution". I selected that and rebooted. IDK if the Pi4 has the same config( i only have a ZERO and a 3B+... and am also quite green in the ways of Pi). That change fixed my issue. Not sure if that is the best way, and i haven't done much testing to see if there are other issues caused by that fix. Best of luck. -D

@simpleethat No worries mate thanks for your help.

It's good that this is documented so if it happens to somebody else they know how to fix it.