IMHO, this is not the problem in osTicket.
Please open your \include\class.ticket.php file and find this code around line 518:
//Send Notice + Message to assignee. (if directed)
if($alertstaff && ($thisuser && $staff->getId()!=$thisuser->getId())) { //No alerts for self assigned.
It said that: No alerts for self assigned. It also mean that if you as a staff who created that ticket, then there will be no alert sent to your email at all.
Sincerely,
Masino Sinaga