How to PUSH and PULL if LOCK mode selected.
Go to options > controls options > mouse
Select default profile > apply & save.
Click preset manager > duplicate > ok > apply & save
Click preset manager > reset to defaults > continue.
Click go back > apply and save.
In air > Press and hold Left Click Button and press Mouse 5 = PULL
In air > Press and hold Left Click Button and press Mouse 4 = PUSH
Source https://forums.flightsimulator.com/t/trouble-with-engage-managed-altitude-mode-airbus/467424/3