Why does this Field Configuration have duplicates that can't be removed?

[Marcel Hager]

I am auditing various configurations in our environment and came across something that I've not seen before, where it appears that there are duplicates of certain fields. This doesn't appear in all field configurations, so I'm not sure if I'm misunderstanding how this should be displayed.

I attempted to delete one of the "duplicates" as a test, and while the field is shown with a "Removed" label, when refreshing the fields are back again. I have confirmed that there aren't actually any fields with duplicate names, only on this screen. Has anyone else seen this and what is the cause/solution? Thanks!