F13-20 Buttons aren't Bindable

I am using a Logitech G502, and today I updated my logitech accessories software to using Logitech G HUB. I did this because I wanted to be able to change some buttons from being useless (dpi up/down etc) so I could perhaps use them.
Therefore I rebound the keys that arent LMB, RMB, and MBB to the F13-18 keys. This works and the buttons show up on button tests however there is no support for them to be bound in-game.

For example I want to rebind bound skill 2 to F14 from Mouse 4(the same physical button I was using prior to the change) but nothing happens. It reverts to the previous state as if I had cancelled the rebind. I then try to use a different button on my keyboard, F11, and it works as expected. I then try to rebind it from F11 to any of the buttons I had remapped, all of which return the same result as before.

Is there just no support for F13-20 to be bound or could there be other problems I've made for myself?