Black Screen Problem with Ubook X persists

my tablet still has the problem that the internal screen is not working. As i can quite certainly rule out a hardware defect, the software seems to be corrupted somehow.
Chuwi already sent me a BIOS-file, but flashing it onto the device did not fix my problem.
Researching online I found out that Chuwi devices tend to drop the GOP (responsible for eDP-output) from the BIOS under certain circumstances.
Can anyone confirm this? If so, are there any fixes?
Chuwi still thinks my panel is broken and it would cost north of 200$ to fix.
Any further ideas?

I have the same problem after a bios factory default… I need help as well…