Hi Tom,
OK, I see what you do in the video but I want to make sure all the scenarios match up.
When I am working with a feature service or data coming from an enterprise geodatabase, either in ArcMap or ArcGIS Pro, I see that we sort the GlobalID fields by the last set of characters.
Ascending: {E13D9E6D-06CC-4CCF-9BC6-0011D61A3DDB}
Descending: {66595284-1337-4B3C-B315-FEE424F42CF0}
However, when working with a mobile geodatabase, we sort that same GlobalID field by the first set of characters. We also sort this way for a file geodatabase.
Ascending:
{091A6365-E29F-487A-A063-3376D024AF24} |
Descending:
{898F25E2-5740-450E-8E04-1441F3F51ECC} |
I see this same behavior in both Desktop clients and at different versions of each so it does look like this is expected. But from what you are telling me, you see ArcMap sort feature services and enterprise geodatabases by the first set of characters and not the last? If that is the case it may need a Support case because that isn't what you should see based on testing this here.
Jonathan