Perhaps you already figured out but maybe this helps others:
I swapped positions 9 and 10 and it worked after a reboot. So I saved 1 2 3 4 5 6 7 8 10 9. Now i have forward on the thumb down button. Right now the wheel click has no function (or none I’m aware of).
Make sure you first go back one step in a website so to be able to go forward.