Network sites aren’t accessible (page not found)

I tried creating a test site with the site name being sidianmsjones.

I got the confirmation email after it was created which says:
Your new MyMythos | Personal Mythology Community site has been successfully set up at:
https://sidianmsjones.www.mymythos.orgmymythos_org/

Obviously the url is pretty messed up looking, but I’m not sure what is causing this and how to fix it :\