PC Version rebinding keys issue:
If you rebind a key to one that is already assigned (e.g., rebind map to G which is assigned to grenade) it will warn you that you need to clear the other binding, press ENTER to resolve conflict.
DO NOT PRESS ENTER.
Cancel the binding, find the conflict FIRST, then rebind that key to one you know is not being used. Then bind the original to the new key, then bind the conflicting one to the key you want.
If you rebind a key to one that is already being used, the binding it is attached to originally will NOT work no matter what you assign it to and you will have to delete your keybinding file and start over.
Clear the conflicts FIRST, without pressing ENTER. The game DOES NOT clear the conflict for you.
If anyone else ran into a bug where rebinding a key on PC made it so that action no longer worked, even when you returned it to default (specifically for me it was the grenade key), you need to delete the original keybinding file, which is hidden away here: