[tafmasterpl]

Hello guys, i’ve got very strange problem, i’ve noticed recently that my rear right passanger door is not locking up, all other 3 doors driver’s/front passanger and left rear passanger are fine they are locking up good, the right passanger rear is not locking up at all, when i close this by pushing black head/tip(im not sure how to call this in english) the doors stays locked for good, even when i close up or open the car by remote the black tip/head is still in the hole and doors are locked so at least no one will rob me of my belongins, and the only way to open up the door is by a handle from the inside.
My bimmer is 2012 335i xDrive:
VIN: F139235
I’ve read it might a be „door actuator” and i’m thinking about ordering the part and fixing this up, but before i do this, could you guys tell me is it for sure the „actuator” or maybe something else might be broken is it a typical case for actuator or maybe it’s not common behavior for actuactor.
What parts do i need to order to fix this up because there is so many options here and i’m really lost what do i need for right passanger rear door, and tell me what i can do before ordering new parts to fix this up?