If you package with Development instead of Shipping, you can grab the logs, might give you a hit of what’s happening.
My guesses:
- the hosting client calls “open ip” too, so it tries to connect to itself → failure → return to menu
- if that IP is external, you need to open the 7777 port on your router, and forward it to your PC
Also don’t forget, for the hosting client, it’s important to open the level with the “?listen” in the URL.
Of course, this is all assuming one of the client is the hosting machine, and we are not talking about dedicated server