Hi:
Hi have a problem with jira service desk cloud.
Note: I have activated the option for customers to add people. this is not the problem.
But when a customer reply a issue (in subject have the id, create a new issue id)
Example:
Original ticket: SE-388
Subject: Not found button.
Customer: userA@pepe.com
CC: distribution_list@pepe.com (Request participants)
But userB@pepe.com of "distribution_list" reply and CC: distribution_list@pepe.com
Create another issue SE-411 BUT in subject have the original issue:
Re: SE-388 Red dos - No ingresan mensajes
Why not add like a comment this mail and a userB request participant because in the subject have the SE-388
Sorry for my english, is bad 
Regards.