Black screen in shipping build (Not editor startup map issue)

My project currently has a main menu (Slate) to host/join an mp game with a simple test scene which is loaded when the game type is selected. A character is then loaded when the game begins. I can package this up in a development build and it runs as expected.

If I change the configuration to shipping however, the build runs and displays the main menu normally; however when I host and select the game type, the window turns black and the level is never displayed. With the console stripped out and no logging, I’m unable to tell much about the cause as the game doesn’t crash. The assets are consistent across both builds.