First of all, I've found this topic, but it's marked as "solved". So I decided to create new one.
A detailed description of the issue.
In F1 2020 I cannot join any of multiplayer session. When I go to unranked I can see list of open lobbies but if I want to join any of them I see joining message for quite a while but then failed to join to session. In the same time other people in lobby see me trying to join.
But in F1 2019 everything works fine, I can join lobby and play multiplay