I thought I would try my th8a gear shifter with my g920 wheel on horizon 4 on pc usb , made a new control layout and then set up my 7 gears and reverse then I saved settings , I went in to the game and only the 7th gear worked, so when I go back in to controls settings the gears have changed to undefined apart from 7th gear , so it feels like its not really saving my settings properly .tired it a few time and the same , just wondering if anyone is having this problem or a fix.
Same here with a Fanatec v2.5 and Th8a. The settings dont saved. Sad.
Same here with a Fanatec CSL Elite Wheel Base and Th8a. The settings dont saved. 
It works in the demo. On the PC.
Same here:
Fanatec Porsche wheel and
Trustmaster TH8A shifter via USB.
i can edit the gears and if i save and exit, nothing abaut the shifter keys was saved.
PLEASE FIX THAT MICROSOFT!!!