Can't make server visible outside LAN

[Benjugglin]

I know this sort of question has been asked here loads of times, but I've read through a bunch of those posts and I still can't figure out why this isn't working.

I reserved a static IP for my computer and set up port forwarding for port 11753. I also set up rules in my firewall for port 11753, so that wouldn't get in the way. If I start a server, canyouseeme.org tells me it can see my service on 11753. Everything seems like it's working, but I still can't get anything to show up on the master server list and no attempts to join via hostname/IP have been successful either. It shows up when on the LAN, but everywhere else...nothing. I've confirmed that my network version is the same on both machines (0.3.5.1-0). I'm no networking expert, so I've pretty much run out of ideas.

Does anyone out there have any thoughts? Anything I can try that might get this to work?