asus ux434flc screenPad show nothing

I have an ASUS ZenBook 14 UX434FLC. The ScreenPad works fine as a regular touchpad, but the display shows nothing (black screen).

What I already tried:

- Used Fn + F6 to toggle ScreenPad modes.

- Installed/reinstalled the latest ScreenXpert (ScreenPad) drivers and ASUS System Control Interface.

- Updated Intel and NVIDIA graphics drivers.

- Updated BIOS and Windows.

Despite all this, the ScreenPad display still does not work. Since touch input functions normally, I suspect this could be a hardware issue (ScreenPad panel or cable connection).

Has anyone experienced this problem? Is it more likely a driver conflict I missed, or a hardware failure that requires repair/replacement?