I have a hosted feature layer on Portal that I want to enable attachments for. I enabled attachments for the layer in ArcPro and overwrote the web layer. Now, when I open the attribute table for this layer in New Map Viewer, the table is blank. The table says it contains records (and I can see my features on the map), but I can't see them. When I open the layer in Map Viewer Classic, the table is populated.
Assuming that the attachment field was the issue, I disabled attachments and the table populates fine in both versions of Map Viewer.
Open to suggestions!