Pi CM4 with buggy integrated screen

Hi, i recently got a Raspberry Pi Compute Module 4 with an integrated 5" 720p touch screen (The reterminal from seeed, https://www.gotronic.fr/art-reterminal-5-cm4104032-34217.htm), and when it is powered, it does a weird visual bug, except for the little left area of the screen, which is not buggy, does this already happened to you ? Could it be the cables or something like that which are not properly connected ? I correctly install the driver for the display, and when i connect it to an external monitor via the HDMI port, it doesn't do the bug, so it's well the integrated screen which has a problem

Pretty sure this is due to a bad connection in the display connection.

Ok i unplugged and replugged the integrated screen connector, exact same problem, could it be the cable which is dirty ? Should i clean it, even it doesn't seem to be ?

Clean with isopropanol or similar, because it could be grease that is "invisible". Is the flex cable damaged? It could also be the display. Is reterminal under warranty?

I can't clean it now, i will can later, but can it be due to a shock, because it fell, it has the problem since i have it, but i got it from a dashboard of a Renault car which was going to be thrown away so a person from family gave me the dashboard, so i reinstall Raspberry Pi os on it, i even have footage of it, before reinstalling, and the bug is still here, with the old os. The person who gave me said the car was not going to be thrown away due to the dashboard which was malfunctionning, but something else.

And no, the flex cable doesn't seem to be damaged (at least the visible part):

There is a connection between the LCD glass and the PCB that could have got "bad" and to clean it is a fiddly task and you need to dismantle the unit completely and the chance to get it right the first time is less high.

I don't think it can be dismountable, I don't see any screws...

Well I don't think I can assist you any more, out of ideas.

Ok thank you, i haven't cleaned yet, i will do it, i will tell you if it fix the problem or does something else