I checked the second tutorial and it’s outdated - no idea of websockets. Jitsi-meet is evolving fast, and even stable and unstable versions are currently very much out of sync and need different steps and you don’t seem to be aware of it.
Quick install by following prebaked stuff is appropriate for a single server setup, for multi servers you need good networking knowledge and more study and understanding. There is better stuff available I think (check @emrah’s posts and github repo for example), but click and run without understanding is ultimately a bad idea.