That’s not exactly true.
Zammad does automatically merge tickets from the same sender with the exact same subject in a limitted time frame after initial creation.
Hard to tell what’s going and how long the time period in between is.
In my case was 1 hour 30 minutes.
100% same subject, same sender and recipient, only difference in the body is “warning” and “success”.
It´s from a monitoring system mail to our support address.