I did Windows 64bit for each type of build. I tried development, shipping, and then debug.
The steam ID 480 worked on all builds expect the shipping version and it worked when launched in stand alone game mode. My app ID didn’t work on any of them.
Have you tried changing the RelaunchAppId variable in function ConfigureSteamInitDevOptions in OnlineSubsystemSteam.cpp to the required custom one? That is the AppId it will use when in UE_BUILD_SHIPPING.
I am marking this topic as resolved for tracking purposes, as we have not heard from you in a few days. If this issue persists, feel free to respond to this thread. For any new issues, please create a new Answerhub topic.
That post was nothing to do with the issue. The guy in the forum thread seems to have got the guys at steamworks to help, it’s something on there end that they need to do.
This seems like an important thing to make people aware about
I can now confirm this is the case, you need to contact valve and they will add the packages for you, by default they seem to be missing. Once they have done this (they did it within minutes of posting) the custom dev app ID works. It might be worth adding this to the steam works page on the UE4 docs.