Managed Altitude Mode A320

No matter what I press on the bravo it never activates the altitude change (in the A32nx).

The buttons work in that they turn the Modes on in the auto pilot but it won’t ‘pull’ the alt knob in order to initiate the managed climb. I looked to see if this needs to be mapped somewhere but couldn’t see anything.

Am I missing something as other people don’t look to be complaining about this?