I've had this issue with a couple of datasets now, and can't figure out why. Can anyone offer any insight or should I log it with Esri support?
Example:
1) In ArcGIS Pro, created a polygon layer and a point layer.
2) Used the instructions here to relate the tables (as aim is to use in Field Maps): https://support.esri.com/en-us/knowledge-base/how-to-set-up-related-tables-in-arcgis-pro-for-use-in-a-000028010
3) Tested the relate by selecting a record in the polygon table>ribbon>Table>Related Data>Click on the Points table that shows in the dropdown>opens the related table (even if there aren't any actual records in the related table). All good.
4) Shared into AGOL.
5) The relate works fine in AGOL, can see it in the AGOL tables, pop-ups etc, works in Field Maps.
6) Add the new AGOL hosted feature layer version into ArcGIS Pro. The relate works fine in the ArcGIS pop-up pane, i.e. the polygon layer can be expanded to show the related points.
7) But the method from step 3 doesn't work - if I got to Table>Related Data>Click on the Points table - the table does show in the dropdown but when you click on it nothing happens. In the GDB version (i.e. in step 3), the points table opens and has the related records selected. In the Feature Layer version the table just doesn't open and the related points do not get selected.
I've tried it by using different fields for the relationship, i.e. not the GUID/Global ID. I've tried sharing to AGOL from right click>Share as well as the Share>Web layer on the ribbon, with the same results. Ideally staff would be able to view/manipulate the data fully in Pro as well as AGOL, so I really want to know what's happening.
