Well, I am not sure if it’s because of plugin or UE 4.21 Source Build. However. I am using plugin just to get SteamID, Avatar and Name (do not use steam servers, but our own).
Before upgrade I was using 4.19 and everything worked. After upgrade to 4.21 clients could not connect anymore because of incompatible_unique_net_id.
Just trying to figure out what cause this problem (but now I think it’s not related to this plugin).