SCORM Data To LMS

One thought: 

You say: "...in the last 6 weeks[.] I tried republishing and replacing the SCORM file, but got the same result." We have had minimal impact during this same time period but I have observed a great many comments here in the ELHeroes about impacts from the different SL versions released during the past couple of months.

Have you tried reverting to the version of SL that was used when the material was initially published?

I'm not a SCORM expert (heaven forbid!) but I believe it would be reasonable to conclude that the failures you are now seeing could be the result of different values/data buried deep in the SCORM package that have been introduced by later versions of SL. So reinstalling an earlier version could be a fruitful effort. Just a thought.