Right on thanks! That's a big library, sadly my library is way smaller than that so I may have trouble figuring out how to test huge libraries without help from folks like yourself, appreciate it.
So you're able to log in but it shows no albums? Are you able to upload screenshots of what you see via TestFlight?
FYI, currently there's only two times where a sync occurs, when you first log in, and when you manually press the "Sync" button in the settings.