It may be too early to tell, but it is looking like multiplayer might be broken. I opened 3 instances of the game to multiplay with myself (as I normally do because there's no other way to create a custom party), and had to copy/paste the game ID because I could not find my own LAN game session anymore. Now my characters are all set and ready to venture forth... and I've been on the loading screen for about 15 minutes without a bit of red in the progress bar.
Anyone else experiencing problems with multiplayer?
Nope. I made two custom characters just like you did. No issues whatsoever.