I don't know if you have the exact same problem but I just figured out what was wrong for me, if installed correctly, you MUST port forward ports 80, 443, and 3306. I had another program using 443 so I did 886 and forwarded to 443 on the public ip and it gave me a 504 gateway timeout. I changed it to port 443 on the computer and it worked, so I think it is very strict on the way it handles ports. It HAS to be 80, 443, and 3306 or it doesn't work. Anyway, I hope I helped, thats what fixed it for me!