Maybe a little late for the party, but we had this issue on some of our systems now and created a script that will look for these missing entries in cp2_product_content and can regenerate the missing entries:
Unfortunately, we also were not able to detect the root-cause that removes those entries 
The issue has been reported on Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1931027