Hi, sorry for my english writing ^^.

got almost the same issue, the key have disappeared from the keys configuration menu since the last update.

/BUT/, it's still working for me.
I configured the [Z] key previously to replace [ctrl] for stance adjust(actually [W] in my french AZERTY keyboard) , and i can use it at well.
But i want to change the binding, and i can't.
I looked at "infantry movement", "common", "view" and "weapon".

I always use this feature IG, with WASD and im sad...