m17 R3, Tobii Eye Tracker device not found

Hello all, I have an Alienware m17 r3 with the Tobii Eye Tracker - I've had had the laptop for 5 yrs but never actually used Tobii in games, only for the auto dimming function. Around Nov last year it just stopped being detected by the sytem, even the little light is off so not powered I suspect. The only Tobii device active in Device Manager is the "Tobii Touchpad Filter Driver". The screen module on which the Tobii is mounted was replaced with a refurbed part by an Dell Partner technician two years ago, just before the warranty expired. Anyway, for a few days now I've been trying to get it to work again, scouring forums and Tobii/AW support articles and trying everything suggested. So far I've done the following:

• Windows troubleshooters
• Dell auto diag program, refreshed drivers. It pretended Tobii was never part of the config, no error about the missing device
• Repeatedly reinstalled and uninstalled the drivers, including with Revo Uninstaller Pro. After the first uninst the Tobii Experience app wouldn't install, missing dependencies (due to the device not being detected I suppose)
• Tried forcing detection every way I could think of, including by disabling/uninstalling the camera and reinstalling the monitor
• Went through the Windows power settings
• Poked around the BIOS, wasted hours trying to get it to boot into the UEFI GUI, hoping I can find more settings there that might solve the problem, or at least see some indication that the system either sees the device or acknowledges its absence
• Reset my Win10 install, then did a format of my sys partition and installed a fresh Win11
• Now after installing the drivers I managed to install the Experience app, but still no luck, Device Manager still only shows the "Tobii Touchpad Filter Driver"
• Tobii Experience troubleshooter only gave me a generic message (error 0x001)
• Ran the full Dell Diagnostic, as it didn't see the device at all it didn't give any errors, even though it was fed the service tag so had to know that the device was missing.
• Finally ran the Pre-Boot Diagnostic, in the PCIe test it shows Bus 02 as "Link Not Reported, Slot 02 Empty", and for Bus 06 it says "Link Not Active, Slot 01 Empty"

Does anyone know if these PCIe Bus messages indicate a hardware problem or is there a software fix?

On another note, does anyone know what happened to the UEFI BIOS? I seem to remember it being bootable years ago... Now it only shows the good old legacy one