Need some serious help with steam multiplayer setup

I have been working through a Unreal YouTube tutorial as seen here: . The problem is I have setup a lobby that launches through steam and the internet and the host starts up no problem. The joining party can find the game but when they connect they get a black screen. If you know how to read logs and look at the errors (Which appear to be mainly the steam. Ignore the duplicate inputs)I would really appreciate it. The join log is the first set in the google link below. The host follows. I have been at this error two months and have tried to get this to go with several different people.…ILDo5fQpM/edit