Resolution issue

I have an issue with my build where its not displaying the correct resolution.

I have a 4K LG display (3840×2160) running over DisplayPort but my machine will only display 2560 x 1440. I can't get it to go higher. I have no idea what happened. I set my config file correctly for high resolution monitors too.

Parts:

i7-9700K

Asus Prime Z370A-ii

HyperX Predator 2400MHz 16GB (2X)

Samsung 970 EVO 1TB

Fenvi T919 Wireless Card

Noctua NH-U12S Chromax Black Cooler

Corsair HX750i PSU

https://preview.redd.it/0mzrvuygbic51.jpg?width=4032&format=pjpg&auto=webp&s=b4ca2ce9d2bad30942ef794dc4ee7287f3d0a03a

Opencore

SMBIOS: macmini8,1

(yes, I'm not running dedicated graphics to keep my power consumption low. I don't need too much GPU power right now)

Thanks guys.