by Ken Task.
Is your development course (without users) a mirror of production course?
Issue might begin with the backup made from development to use merging with production.
So let's say in development course, there are already Video 1 and Video 2 in Section 1 of the course. You add a Video 3 to it. Then, when making the backup, one selects only Video 3 to include in the backup you intend to merge with production course.
Is that your process?
'SoS', Ken