When I try to create a GeodatabaseSyncTask with credentials it Always returns 401 unauthorized, even when the credentials are right. Here is the code that I'm using right now:
System.Net.NetworkCredential networkCredential = new System.Net.NetworkCredential(userName, passWord, domain);
var credential = new ArcGISNetworkCredential
Credentials = networkCredential,
ServiceUri = featureURI
GeodatabaseSyncTask gdbTask = await GeodatabaseSyncTask.CreateAsync(featureURI, credential);
I don't know if my code is wrong, but I've tried it on iOS (API100.0) and old .NET api and it worked fine!