Replies including two groups only update the ticket in one group

Infos:

  • Used Zammad version: 6.3.1
  • Used Zammad installation type: Deb
  • Operating system: Ubuntu 22.04
  • Browser + version: Any

Expected behavior:

  • Replying to a message including two group email addresses updates existing tickets in both groups.

Actual behavior:

  • New message is only added to a ticket in one group.

Steps to reproduce the behavior: