Steam Session no longer working with new steamID

I’m really puzzled by this one and been trying to debug for several days but totally stumped.

We’re working on our multiplayer game at the moment and integrating steam into this. I managed to get past adding the SDK and such to the engine and made a build with the default 480 space wars steam id. Whoop everything going well.

So swap out the spacers id to our own games steam id in the default engine ini (change nothing else) but now it it fails to create any sessions.

Really confused and not sure where I’ve gone wrong. Anyone got any idea or had this problem in the past.

(we’re using 4.13.2 if that helps)