Broken Synch on IOS

I’m having an issue with my IOS app where synch becomes disabled. This has happened twice with 2 different users. I created a topic when this happened previously here

Basically, a user created 2 records and they were successfully synchronized. Days later, the user created 2 more records and synchronization has broken.

The last time this happened, I never found a solution. There were no client errors. The db continued operating fine locally, it just wouldn’t synch. I ended up deleting the account and starting over. This time is more challenging because I don’t have access to this user’s device. The best I can do is send beta releases.

So I know it’s a stretch and there’s very little to go on here, but I’m hoping for some suggestions on how to begin to try and debug synchronization issues. Or, are there any known issues that might cause a synchronized account to lose synchronization?