I have metadata for a hosted feature layer in AGO using ISO 19139 Metadata Implementation Specification. When I go to Item Details > Metadata and make a change (or don't make a change) and click Save, then open the metadata again, I see "1 2 3" added to the Resources > Constraints tab, as in the image below:

Every time I save, close the metadata editor, and then re-open it, these numbers grow to 5, 7, 9, etc. even though I am not adding more items to that tab. Is this expected behaviour?