Since the port 9999 is working for https connections, try visiting the page if you can via
https://Localhostaddress:443. Things do look correct though in the web server and in no-ip's settings. Also, if Abyss Web Server is not acting as a DNS server itself and is just listening for data that comes in via a specific port, that may also be causing an issue for you where it's trying to connect to it via your modem/router. I've never tried using https connections back when I ran a server at home so it beats me right now unless I think of something else.