Trouble uploading SCORM content and courses using REST and HDL

Content

We are loading many courses and content together using both REST API (for Content Objects and Akamai file upload) and HDL for the Course, Offering, and SelfPacedActivity objects. This process was working well earlier this month.
We started loading courses for the first 8,000 courses we had 98% HDL load success. The 2% errors were all: "The values ... aren't valid for the attribute ContentId."
But looking at a Self-Paced Activity for an imported object in the UI, where it shows the associated content looks weird. It has a link that says "Clear {Media_Type}" instead of something like "Clear HACP". Also, The Learner can enroll in the same course, but not launch the content.