Game Master mode on TCL 50C735

[aracno]

Hi,
i just bought this TV only for PC Games:
https://www.displayspecifications.com/fr/model/9a852c21
So a quick sum, the TV is HDMI 2.1 and the panel is 4k@144Hz capable.
When connected to my computer (RTX3090), i only have 60Hz resolutions.
So i try CRU to get 4k@120hz with no luck. I only can get 1080p@120Hz.
I notice this in MonInfo on all 3 HDMI ports:

Code:

Timing characteristics
  Horizontal scan range.... 30-80kHz
  Vertical scan range...... 50-75Hz
  Video bandwidth.......... 600MHz

Video bandwidth should not be arround 1190MHz for 4k@144Hz?
After a call to TCL hotline, the guy told me that this resolution is only supported when a game console is detected (aka xbox series X or PS5) and then the TV switch "Game master" mode on (aka "game mode" for LG or Samsung).
I dont have next gen game console, so i can't test it.
I've attached moninfo result and dump of the TV EDID.
If someone can point me the right direction to get this TV at 4k@120Hz with a PC...
Thank you.