I have a seperate keybing for stand up and crouch (V & C respectively) and they don't work as intended, I've reported this bug in 1.12 and got no reply.
If you set a keybind for crouch, it will not stick to crouching but will instead toggle your stance with each press of the button.
If you set a keybing for stand up, pressing it will make your character crouch and uncrouch.
Please fix this as its a pain in the ass when keybinds don't work as they're supposed to.