Replication Advice Needed

I successfully set up Dovecot replication, having 2 servers syncing with each other. While I had both servers in the same room on a Gigabit network, they were syncing fine. But I took one to another location, and syncing was turned off for about 2 weeks. Now I've turned both back on, they're sort of syncing, but not really. The one remote server is not populating emails into various folders and it really should be cranking to sync those emails.

Do anyone have any insights on how we could troubleshoot this?

-- --Asai