Door v2 mounting tips

Hey, not sure if this is the right place to ask . I’ installed a Video Doorbell v2. The original doorbell was installed on a rock surface (looks like ledge stone or cliff stone) instead of the door frame. I didn’t do the original install, just trying to work with what’s there.
Now I’m having a hell of a time getting the doorbell to snap onto the mounting bracket. There’s also a big gap because of how uneven the wall is, so I stuffed some duct seal putty in there for now to fill it in.
Could really use some tips or advice if anyone’s dealt with this kind of setup before

How tight are the screws securing the bracket to the wall? That’s my first thought. If you really crank the screws down, then that can cause the mounting plate to flex or bow a little and then put the lugs or tabs out of alignment with the slots on the back of the doorbell camera. If you have a little room to back those off (maybe not even a full turn per screw, depending on what your mounting location is like), then that might allow the bracket to straighten out enough so that sliding the camera module onto the mount is easier.

With an uneven surface like that—or at least what I’m imagining based on the description and without images—you might want to look at trying to provide some kind of rigid flat backing for the mounting plate or some other means to fill in whatever gap you have behind the plate. My own Video Doorbell v2 wasn’t giving me the downward angle I wanted, so created a different bracket for a 3D printer that gave me the desired angle and covered the microSD card slot. I mention that in case you have access to something like that (I did mine through a local library) and potentially need to customize a mount for your application.