Alternate Button preset bug (Xbox)

BUG: There's an issue using the Alternate buttons setting when using a bipod (Xbox). Using the B button still uses Crouch even though it's set to Melee, and using the R3 to mount the bipod just makes me stand up. Even when using button mapping to make Deploy Bipod assigned to the B button (an obvious swap compared to the Default control setup) you still Crouch instead of deploying. Using the B on this setting also completely takes away your Melee, even though it shows it's assigned to B.

UPDATE: After more trouble shooting, I was able to set up a bipod/mount a weapon as long as I keep ADS and holding down the B button (against an edge and while Prone) . However, it doesn't happen every time. Regardless the B button still isn't able to use Melee and still Crouches (but interestingly can't hold B to go prone)