Flicker on startup c27jg56qqu

Greetings!

TL;DR - monitor flickers in a vertical wavelike gradient patter with distorted colours for a while after turning on, but works fine after a few minutes.

My Samsung c27jg56qqu monitor, if not used for a while, does a weird flicker (not the LEDs, but the pixels themselves behave weirdly) when turned on - a pinkish white gradient goes over the screen in a vertical way (top-down), usually making it so that the very top of the screen is legible (around the width of a browser tab bar), and everything in the middle is blurred/stretched out. This gradient sort of "flows" and moves in a wave like pattern. The mouse pointer, for example, if its in the middle of the screen and i move it, i see a white blur stretching from the position it was moved to the very bottom of the screen (sort of elongating its shape, stretching), and disappears when i stop moving it completely. This continues for longer if the room was cold, and can last for up to around 5 minutes sometimes if the room was especially cold.

I opened it up and took a look at the PCB, but nothing obvious like burnt chips or passive components was there. Nothing changed if I wobbled the wires back or forth or tapped on components, so to me it did not feel like it was loose solder joints (like some search results suggested), but maybe I missed something. its bothersome to test, since i have to disconnect everything, wait for it to cool off, and connect again, with limited time, as this effect disappears after a while.

This only happens with the DisplayPort connection, which is the only 144Hz 1440p input of this monitor. Different DSP wires change nothing, different GPU outputs change nothing. Different GPU changes nothing. Has to be within the monitor itself.

This all started around the time i had left house for around a week with windows open during a very hot but windy and humid summer, with the monitor on standby (pc off, all wires connected).

I have also noticed that before this issue started, the monitor has always been flickering brightness in a barely noticeable way when outputting in over a 60Hz refresh rate - it is only visible if you focus on it. Maybe this is related. One of my previous DisplayPort cables was also killed completely after only 1 year of use.

I was wondering - maybe someone here has experience dealing with something similar, and can point me in the right direction of what components exactly I should be focusing on the PCB to isolate this problem.

Edit - i would also like to add that i have a soldering station, multimeter, etc. and i am comfortable using these as my work is related to buiding my own circuits, PCBs and devices, but not in a too advanced way, as its not the main focus. I am also no stranger to reading and understanding integrated circuit data sheets and all that jazz.