me too , argh.
8.3 went smooth
finally got it after literally hours of trying
win10 32 bit, 12.0.1, 12.1, 12.2, custom drivers
win 10 64 bit all the same
En and chinese, on power through the adapter, and through USB-C to USB only, and all combinations and finally worked.
No idea what finally got it going but wow, worst jailbreak process ever from my experience.
at least it is done. debating whether i want to wrestle with this process on my ipad mini or not, luckily i havent even really set up 8.3 jailbroken on my ipad to my liking so it will be less once I get past the hurdle, but GEEEEEZ!