Ben, Thanks so much for your reply.
The team here with me also couldn't figure out why every time I clicked to add a test between certain slides (ex: between Slide 10 and 11) it would pop into the TOC in a place where the previous designer has already placed a test section (between slide 20 and 21).
I also tried to add a plain section between 10-11 but it also jumped down to 20-21 place in the TOC. The workaround was dragging all the slides (1-20) into the test and then dragging them back out one by one in order in front of the test. It seem to break whatever was locking down the first 20 slides of the course.
Again, I appreciate the reply...hope no one else has this problem.