Having problems trying to playtest my game in standalone mode with a friend using Advanced Steam Sessions?

I’m using Advanced Steam Sessions for my multiplayer. I’ve done a lot of research and tried a few things but havent found any results.

I want to be able to speed up playtesting my multiplayer game with my friend. Currently to test it I need to build it out and send over the game files to them. If my friend and I both launch the game in engine through the standalone mode when they attempt to join my server they successfully find it and connect but are not loaded into the level. In a built version of the game they do load into the server correctly.