Wondering if someone has come across similar issues that we see with syncing. This is in addition to the bug introduced in 10.5.1 that makes sync fail completely. Which has kept us at 10.5
In our scenario we do a pre-planned workflow using an archive enabled non-versioned database (based on being strongly suggested approach by esri). The replica file is shared to our users by moving them to the device and then using the RegisterGeodatabaseAsync to register back to the server. We do see the replicas when looking at the feature service through the web interface, so they exist.
In this process the users are named users who's credentials are passed in to create the GeodatabaseSyncTask used in calling RegisterGeodatabaseAsync. The ArcGIS Server is federated to the portal. Our users are Level 2 - Users.
What we see is that users are unable to sync in this situation. The only way to get sync to work is to raise the level of the user to a Level 2 - Administrator. When the user is advanced to this permission level everything works fine. What I find odd is that the Level 2 - User can create the replica (or register it depending on the terminology you want ti use). But that same user cannot sync this replica. If you look at the data it defines our Level 2 - User as the owner of the replica. So, the owner of the replica is unable to sync the replica.
Anyone else has a similar setup, and seeing different results. We have seen it in two completely different environments so it seems not associated to something done in a non-standard way.