Thanks for your answer!
After some testing I noticed that the tickets are associated with the user and not whith organizations. So when a user moved to another organization, their tickets follow the user.
We are a voluntary organization that operates all over the country and our members (users who open tickets for support in a centralized structure) often move from one department (organisation) to another. In our case, the goal is the tickets to be associated with both user (who opened it) and the organization that opened it.
There are automatic collaborations - assignments, but if after a while all the members of the organization change - moved, the newest will not see any of the previous tickets.
The management of support agents is perfect and really can do everything!!
I will continue testing and if I make any progress I will report back.
Thanks again