RTX 2060 High GPU usage with external monitor over USB C

Graphics / Linux Linux
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1

I have a laptop ASUS TUF506IV-AS76 with GPU NVIDIA GeForce RTX 2060 and an external monitor Acer Predator XB323QK which has several options how to connect it - HDMI, USB C, DP, even USB 3.0 it would seem.
Connecting it over HDMI with 3840x2160 @ 120hz i get a very weird red color output on the monitor, any red text or element over black/dark background looks pixelated and screwed up. No amount of calibration or option fiddling fixes it.
However, changing the refresh rate to 3840x2160 @ 60hz does fixes this.
The laptop has HDMI 2.0b port.

Now, i tried connecting it over USB C and there is no display issues at all and i can get it to 3840x2160 @ 144hz even.
But when i connect it over USB C, there is a huge increase in GPU utilization without anything except desktop environment running. At 3840x2160 @ 144hz i get like 60-70% GPU utilization, ~60W/90W. When i turn it down to 3840x2160 @ 60hz - it’s half that: 30-40% GPU utilization, ~30W/90W.
Meanwhile connecting it over HDMI does not cause any increase in idle power consumption/gpu utilization at all, regardless of the setting.

It does look like a driver bug, any help regarding the issue is much appreciated.

Sat Jan  7 11:46:34 2023       
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 525.78.01    Driver Version: 525.78.01    CUDA Version: 12.0     |
|-------------------------------+----------------------+----------------------+
| GPU  Name        Persistence-M| Bus-Id        Disp.A | Volatile Uncorr. ECC |
| Fan  Temp  Perf  Pwr:Usage/Cap|         Memory-Usage | GPU-Util  Compute M. |
|                               |                      |               MIG M. |
|===============================+======================+======================|
|   0  NVIDIA GeForce ...  Off  | 00000000:01:00.0  On |                  N/A |
| N/A   72C    P0    57W /  90W |    150MiB /  6144MiB |     70%      Default |
|                               |                      |                  N/A |
+-------------------------------+----------------------+----------------------+
                                                                               
+-----------------------------------------------------------------------------+
| Processes:                                                                  |
|  GPU   GI   CI        PID   Type   Process name                  GPU Memory |
|        ID   ID                                                   Usage      |
|=============================================================================|
|    0   N/A  N/A      1400      G   /usr/lib/xorg/Xorg                149MiB |
+-----------------------------------------------------------------------------+
2

Update: When connected thru USB C the monitor does not wake up from sleep, does not turn on with the laptop and is a pain in general. I’d really appreciate a response here. Is that a hardware problem or the driver is to blame?