"Inserted in" vs "Parent Info"

Good to hear from you again, and thanks for your question.

The “Inserted in” column/meta box is part of the “where-used” reporting. It lists the posts/pages where the item is inserted in the body of the post/page, i.e., where one of the item’s files appears in an < img > tag.

The “Parent Info” meta box (or the “Attached to” column) reports on the post/page whose ID appears in the item’s post_parent field.

I am marking this topic resolved, but please update it if you have any further questions regarding the difference between these two pieces of information.

Likewise!

Alright, that’s makes sense. I just confirmed that “Inserted in” does work on my system, I just didn’t have any media inserted in posts before (only attached).