over 3 years ago - AndrewT - Direct link
I have repeatedly responded to this problem, in here for instance:
forum.paradoxplaza.com

MULTIPLAYER LOGGING OUT ISSUE PERSISTS.

Hello, I found out that host getting logged out issue still persists despite 1.2 patch. Me and my gf played a multiplayer session in hoping for it to be worked after 1.2. We launched the game and firstly played only roughly 3mins to see if... forum.paradoxplaza.com forum.paradoxplaza.com
In brief the problem has been addressed in some game patches and server updates since game release, which reduced the size of the affected user population but not completely eliminated the issue, obviously.

Work continues, I have good hopes for the next patch 1.3.2 which is now in internal testing I believe.

The only workaround known to have helped is connecting via a VPN set to the USA, for some reason.