Can't bind function keys

[keywah]

I have an MMO mouse (12 buttons on the side) and I have my function keys bound to these. I was trying to rebind the melee button from V to F5 and I got a "can't bind to this key" error. I thought it was conflicting, found it was one of the surrender keys, changed it, tried to rebind the melee key again and got the same error. Restarted the game, tried again, nothing. I tried the other function keys, and none of those worked either.

I'm just a bit confused because when you click on a keybind to change, it will show you the available keys in a preview with the function keys present. The function keys can be used to agree or decline a surrender so it's not an issue of them not working.

[Timeraider]

Same, find that weird as well

[Lokrye]

Yea, I can't bind F1-F4 either. For no reason. There's also intentionally no advantage to Mouse/keyboard over controller. This game is not for gamers, just betas who want to pay to dress up their little cartoons.