BUG: Mailbox renaming algorithm got into a potentially infinite loop, aborting

Hi all!

I have two dovecot servers with dsync replication over tcp. Replication works fine except for one user.

# doveadm replicator status username priority fast sync full sync success sync failed customer@example.com none 00:00:33 07:03:23 03:22:31 y

If i run dsync manually, i get the following error message:

dsync-local(customer@example.com): Debug: brain M: -- Mailbox renamed, restart sync -- dsync-local(customer@example.com): Error: BUG: Mailbox renaming algorithm got into a potentially infinite loop, aborting dsync-local(customer@example.com): Error: Mailbox INBOX.Foldername sync: mailbox_rename failed: Invalid mailbox name 'Foldername-temp-1': Missing namespace prefix 'INBOX.'

For more info see the attached sync_loop.log

Thanks for your help,

Alex