Microsoft Azure Sql Data Sync

Question

I've set up a sql data sync that syncs data from our on premises to a azure sql database. The initial set up was eventually done and I successfully got the data to sync. I've set the sync up for every 6 hours.

The problems: subsequent sync seem to more often than not come up with sync failed errors and I cannot work out what is causing the problem and which table(s) it may be causing the issue. the error messages usually start with : Sync failed with the exception "An unexpected error occurred when applying batch file sync_...........

I've only got about 6 tables being built at the moment most are tiny but there is one that has 100,000s of records.

My questions are is this the best tool for what I'm trying to achieve?

I don't seem to be able to rely on the sync working - and it is vital this is 100% working once set up.

Is there a more transparent way of determining what and why the syncs should fail?

Can I have multiple sync groups and is this the best option going forward.

The product seems to be just what I need but I'm unsure if this is the best solution?

Thanks