Customers cannot decide on who is the correct owner of the ticket.
This may also provide issues when customers overload a certain owner while other agents idle through the day.
You can’t change that behavior. What you can do is to update the owner of a ticket during creation via trigger if that’s really what you’d want.
well, It´s (now) only me as agent anyway. So in my case, the auto assignment you speak about woulnd´t be a problem. But I get your point, it doesn´t make sense in general.
A trigger would be fine totally - or assign it to a group of people, and then anyone within the group can grab it.