Tickets get expired in my ticket view

Tickets get expired in my ticket view

Hi all...

hope you are well.
I have seen that my ticket view doesn't display tickets older than 30 days, The view doesn't display tickets even if the tickets have a comment attached. This is getting a huge problem because we lose tickets of 30 days old

How can I extend the "life" of the tickets in my view?
I would like to display tickets at least 100 days old.

Thanks a lot
Marcello