I am not sure if this will help, but have you tried turning the door around the other way, then try to lock it? As I seem to remember someone else on the forum was having the same issue, and it was easily fixed by turning the door around and they were able to get the door to lock.
I wish I was able to remember who posted about it and the link. I even tried to search on it, but wasn't able to find it or anyone having locking door issues, currently.