How to replicate:

1. Create or open a new issue ticket
2. Open the ticket, update transition or change issue status (any status: Pending/Escalation etc)
3. Under comment, Respond to customer field type user name with "@xxxxxxx" -it reverts to the account id
   

      4. Once comment has been updated, the username shows properly

Suggestion: Please also update the transition view screen so that @user mention does not reflect account id when updating the comment field