Hot damn, ISPs are the worst.
Our ISP has oh so graciously provided us with a router to hook up to their network, and it’s an absolute piece of shit. Hell, some of the functionality offered through its interface is straight up disabled. You can see it’s there, but you can’t do anything with it. And the things it does still offer? They’re unsupported by the ISP.
Port forwarding used to work just fine. A little while ago, it just stopped working. No indication anywhere as to what the cause could be. It’s not my local machine and all the settings are correct, so my best guess is the problem lies in the router. It’s too locked down for me to do any useful troubleshooting with though. I tried the ISP support chat, but they couldn’t help because apparently functionality their routers provide isn’t officially supported.
And guess what, chances are no other router will work with their connection.