Even though this topic is a bit old, I'd like to respond because it may still be useful to the author and other users experiencing the exact same symptom since member star try to help, but are not into the electronic field.
This problem is neither the cable nor the GPU, the bug appears when the device is cold, and gradually disappears after a few minutes. It is more pronounced at 144 Hz.
It is almost always an internal hardware problem with the monitor, most likely related to the capacitors (condos) or the T-CON board, which become unstable with age, especially when it is cold.
144 Hz (FreeSync Ultimate/high VRR) puts much more strain on the panel controller, and when cold or capacitors aging, the voltages are not yet stable.
120 Hz is less demanding, that's why.
This is a well-known problem on some modern monitors, particularly thin, gaming-oriented monitors that have smaller components (which are also cheaper, despite the marketing) and therefore less thermal margin and a shorter lifespan, but increased sensitivity to aging.
Unfortunately, this type of failure cannot be repaired by software and tends to worsen over time (longer warm-up time, then permanent failure).
Temporary solutions sometimes include leaving the screen on standby rather than turning it off completely, avoiding rooms that are too cold, or turning on the screen a few minutes before use.
Otherwise, the permanent solution is electronic repair (often not very cost-effective) or replacement of the screen... I know, we pay for screens to last, but welcome to electronic obsolescence.
If it is still under warranty, you can submit a request to Samsung.
In summary:
it is not a GPU bug, nor a cable issue, but a problem of electronic aging + cold weather, typical of many current screens.
