This is very frustrating.. because there is apparently no reason for it. I finished uploading a hosted feature service that contains 7 different featureclasses, additional attachment tables and some relationship classes.
I have enabled editing in the hosted feature service settings and all layers in the web map I created to contain them:
This allows me to add new features in the web map, however, when I attempt to do the same in Collector, I can only add features for HEP_Lines and Locations..
I have discovered that I cannot create new features in collector for features with relationship classes (excluding the relationship classes esri uses for relating features to attachment tables). This only affects creating features in the Collector app, NOT in web maps. It seems quite inconvenient, and I wonder if there is a workaround other than removing all relationship classes from the geodatabase except those for attachment tables..
Any suggestions are welcome and greatly appreciated!