I uploaded a zipped shapefile to AGOL to create a hosted Feature Layer of HYDRANTS.
I can see this hosted feature layer and edit it's points in AGOL.
GOOD: From the item's Overview page in AGOL I can open this hosted feature layer in ArcGIS Pro (2.3.3) via opening the downloaded item.pitemx file and that works fine; I can see the features and edit them.
BAD: However, when I try to open this hosted feature layer in ArcMap (10.6.1) I get nothing.
DETAILS:
1) When I click Open in ArcGIS Desktop/Open in ArcMap from the item's Overview page I get the "item.pitem" download; when I try to open this file, it launches a new ArcMap desktop session, but no data layers are added to the map.
2) From ArcGIS desktop, if I try to "Add Data from ArcGIS Online", I can FIND the hosted feature layer, but when I click "Add" nothing happens.
3) Finally, if I go to Add Data, My Hosted Services, I can see that layer and add it successfully. However, I can't edit it directly. The only way I've found to edit it is via "Create Local Copy for Editing".
I am logged in to AGOL within ArcMap desktop.
Are these differences between AGOL/Pro, and Map expected?
Jay