Seems to be impossible to change this keybind.
When attempting to change it, after clicking 'apply' the keybind disappears and reappears as an empty slot and is renamed as 'Change Camera Perspective DOUBLE TAP'.
When trying to apply a key to this new keybind it resets to an empty slot as well.
I didn't test to see if other keybinds behave in this way. Only the one I talked about.
I also did delete and recreate game files, verifying them thru steam, ect.
However when recreating and verifying the game files it did reverse the keybind to its default settings but problem still remained the same when attempting to change it again.