Issue with dsync server - copy transaction record copying to wrong destination mailbox.

Hello all,

I am encountering the following issue :

I have 2 dovecot servers with 2 way replication. Everything works fine except for one specific issue :

When my MUA (thunderbird) filters (junk & manual) refile a mail from my inbox, I then sometimes find multiple copies of the original message in the destination folder.

I have seen the following log entries which make me think (but I'm new to this) that there could be an issue with the processing of the COPY transaction record during DSYNC :

• TB Marking msg as Junk Jun 22 20:36:14 db04 dovecot: imap(ivan): flag_change: box=INBOX, uid=502902, msgid=<RF7w0iVHwvOBtpFW7y7eTF3jazYxJeuFC9JvB9xsjnk.gI5bQ0w8OtJJT7-T4krQTG3XkEqb5Hti..., size=9942
• TB Copies msg to Junk Mailbox Jun 22 20:36:14 db04 dovecot: imap(ivan): copy from INBOX: box=Junk, uid=32059, msgid=<RF7w0iVHwvOBtpFW7y7eTF3jazYxJeuFC9JvB9xsjnk.gI5bQ0w8OtJJT7-T4krQTG3XkEqb5Hti..., size=9942
• TB expunges mail from INBOX Jun 22 20:36:14 db04 dovecot: imap(ivan): expunge: box=INBOX, uid=502902, msgid=<RF7w0iVHwvOBtpFW7y7eTF3jazYxJeuFC9JvB9xsjnk.gI5bQ0w8OtJJT7-T4krQTG3XkEqb5Hti..., size=9942
• Local server receives transaction from remote server and saves message again to INBOX Jun 22 20:36:16 db04 dovecot: dsync-local(ivan): save: box=INBOX, uid=502903, msgid=<RF7w0iVHwvOBtpFW7y7eTF3jazYxJeuFC9JvB9xsjnk.gI5bQ0w8OtJJT7-T4krQTG3XkEqb5Hti..., size=9942
• Remote server copies message from INBOX to INBOX <<<<<<<<<<<<<< That's my issue Jun 22 20:36:16 db04 dovecot: doveadm: Error: dsync-remote(ivan): Info: copy from INBOX: box=INBOX, uid=502903, msgid=<RF7w0iVHwvOBtpFW7y7eTF3jazYxJeuFC9JvB9xsjnk.gI5bQ0w8OtJJT7-T4krQTG3XkEqb5Hti..., size=9942
• Remote server expunges msg copy Jun 22 20:36:16 db04 dovecot: doveadm: Error: dsync-remote(ivan): Info: expunge: box=INBOX, uid=502902, msgid=<RF7w0iVHwvOBtpFW7y7eTF3jazYxJeuFC9JvB9xsjnk.gI5bQ0w8OtJJT7-T4krQTG3XkEqb5Hti..., size=9942

Is this a known issue (I may not have looked deep enough..) ? Is more information needed ? (note again that for me dovecot is working perfectly fine except for that little issue).

(Version is 2.2.27 from Debian stretch)

Thanks,

--Ivan