[Arena] Why do we get kicked off when losing connection?

Seriously, I was playing arena of the gods, the first mission, and I got kicked off because I lost connection. Why is that ? Why would it need internet connection if I’m playing solo ?

My theory would be that they are working with a onlein lobby. So that coop is also possible at any time. That’s why an internet connection is also required for singleplayers, so that a friend can be invited at any time.