I have purchased and installed as per instructions an aftermarket auto tailgate. What I though would have been an fairly easy job, turns out to be a headache. It has a soft close latch that when the lock engages, it's meant to pull the boot closed. It's as though the lock is trying to pull it too Also when opening the tailgate, the lock doesn't disengage. I know it's a long shot, but has anyone else fitted one of these successfully, or guide me as to where I'm going wrong. It was bought from China, I've been in contact with them a couple of times over a few things, but distance doesn't help.

this is a video of it