Edit: Ok I was wrong…
60/120Hz isnt needed to make the Eye Tracker work. The act of unplugging the top usb-c connector gave the cables connecting it to the 2 glasses/sensor units enough slack to reseat it properly. Either the cables are cut short to fit 8KX who dont have the top usb-c connector to fixate the module, or it might just be manufacturing tolerances. My eye tracker is unfit for 8K use anyhow unless I use an external cable and fixate it somehow since it isn’t held in place by the usb-c any longer.
Old text:
Interesting!
I managed to get the eye tracking to work on my 8K. ONLY if I pull out the ET out of the top usb-c port and connect a verified bona fide usb 3 cable to an usb 3 port on the motherboard. If you have both connected you can get groundplane hum in the speaker, it might hurt the hardware 
+ it will default to usb 2 port and 30Hz tracking… A bit fiddly but works at the moment.
With the Usb 3 connection the non-working calibration suddenly tracks at 60 or 120Hz and sees my eyes! Finished the calibration albeit the tracking isnt supersmooth and it wobbles a bit.