Am kinda like Howard ... confused about what you are asking/reporting/wanting to know ... but, here's a thought ... an apache rewrite rule added to server where even internal links (coming from DB) are re-written/re-routed from http:// to https://.
Many folks do just that when first making the change from http:// to https:// so all the users that have bookmarked/favorited links to the moodle won't have to be reminded to change their bookmarks/favorites.
100% guess, of course.
To see if that were true, one could have to query a table in moodle for url resource links that went to your own server to see if any of those contained http:// as opposed to https://. If some of those showed http://yourownserver/ then would think it has to be a re-write rule.
'spirit of sharing', Ken