dsync initial replication failing

[Cassidy Larson]

Trying to get my new storage server synced up using dsync replication with
SSH.
Followed the wiki and everything works great for the initial sync, for
about 4 hours, then I get some errors and it stops replicating:

dsync-local(user at host.com): Warning: Failed to do incremental sync for
mailbox INBOX, retry with a full sync
dsync-local(user at host.com): Error: Remote command returned error 75: ssh
-lusername <remote_ip> doveadm dsync-server -uuser at host.com -U

It happened around 2am. I restarted the new server dovecot process and it
started to copy back up again, and then happened about four hours later.  I
have about 10,000 accounts, and it chugs through the list to replicate
pretty well (~300Mbps), so I know it's working.  Just not sure why it's
failing after it's working so great.

Running 2.2.13 on both on FreeBSD.

Both show this:
# doveadm replicator status
Queued 'sync' requests
0
Queued 'high' requests
0
Queued 'low' requests
0
Queued 'failed' requests
0
Queued 'full resync' requests
5645
Waiting 'failed' requests
0
Total number of known users   9957

Any ideas? Suggestions?

Thanks,

Cassidy