From Frank Potempa on the Collector forum: Android ArcGIS Collector App Cannot Authenticate with Windows Active Directory
I wanted to add the final information/ clarification to this discussion I received from the ESRI tech;
"While I am not in development and I am just relaying this information, this is what I can tell you. The bug logged is with the Collector for ArcGIS API. Development has stated that they will be fixing the issue in the Collector API for the next time they integrate the API into the Collector application. The new, 10.3 version of the Collector app will not have the new API integrated so it will not be fixed in that release. This indicates that for the time being, to use the work around provided. "
Might be part of the issue?