When I build a grouping list, I like to view the grouping list first to make sure it’s the list I want (by not putting a @ sign in front of the report). I will try different dates to also make sure. If you look at the report tag, it will show all the ticket types. So we need to try a different approach. Since you want something related to tickets, so lets take a look at one of the ticket reports. If you under REPORT TICKET DETAILS there is a field for TicketType. Try that. If that isn’t exactly what you want, you can try putting some expressions in the report to get the desired results.
Also, you don’t need the ! between the @ & {.
On a sad note, @emre passed away last year.