I am currently working the installation of an app for our work force that will to be able to add daily inspection reports at various locations around our city. I have enabled all attachments within my layers of my service, and checked on all possible user executions of the data...be it to create, update, sync, delete. etc... In Arcgis Online I can view my feature class and access my link to my related table just fine. Of course you can not edit related tables in arcgis online. So with Collector I am having an issue, while I can view all my related records and even delete and modify records within Arcgis Collector, I can not create a new related record when I hit the "new" tab at the bottom of my legend tab. The "view" tab works fine and lets me delete or modify existing records, but I can not create one. The tab will not even show the circling thinking activation when I hit it like the view tab. What I am doing wrong? Thanks in advance.
I'm new to editing related tables in Collector, but are you sure you have set up your relationship correctly? If you are trying to add a second record to a feature your relationship has to be 1 to Many, or Many to Many - have you checked to make sure it is not 1:1?
One thought in addition to Elizabeth's suggestion - are you using an on-premise feature service or an Esri-hosted feature service? It may be necessary to check the permissions on the related table to ensure that your colleagues have the proper insert privileges for that table.