Party Unreal OSS: can't connect to peer

Hello,

I'm integrating Party into a UE4 game on XSX. Using 2020.12-PlayFabPartyOnlineSubsystemforUnrealEngine4-1.0.5.

While everything looks fine I just can't connect to the peer that's hosting the game. Playfab party initializes successfully, then I connect to PlayFabPartyNetwork, then endpoints get created. After that, I try to connect, and there are no errors in FPlayFabPartySocket:SendTo() so by the looks of it the data gets sent. After that there's complete silence on both the server and the client. I'm not getting any errors in logs in my title dashboard either.

Hope you can point me in the right direction here. Any help will be much appreciated. Thanks!