The subject of your ticket may change for one of two reasons:
1) Our team members manually updated the subject. This would occur if our team identifies that we are working on a new issue, but the subject references a previous issue. This allows both parties to better search if they need to refer back to find a ticket about a certain issue.
2) The second reason is more serious and it is important that our customers avoid this situation. If you reuse a previous ticket to submit a new issue or PO, it is very likely that your ticket will be merged into the original ticket. When this occurs the new subject will be replaced by the subject of the original ticket since the new information will have been merged into the old ticket. This occurs because even if you clear out the subject line, there is still code embeded in that email that links it to the original ticket.
This will always happen if you either hit "Forward" and then just add your new comments and replace the subject matter, or if you hit "Reply" to a previous email and add your new comments and replace the subject matter.
The only way to avoid this from happening is to always create a brand "New" email when submitting a new issue or PO.
When this issue occurs it is likely to cause confusion and/or significantly delay a response from our team, which we all want to avoid from happening.