I've been trying to fix this for at least 3 months now, and I still haven't got a clue as to why it happens, but port-forwarding simply doesn't want to work on my new ISP (and modem and router). The only thing that works is a Minecraft server. Seriously. I've tried hosting a SAMP server, or playing Max Payne 3 or GTA IV, and all 3 of those are blocked (SAMP server isn't seen by canyouseeme.org, and the 2 games have the same kind of connectivity issues as if the ports weren't open) The Minecraft server works on all forwarded ports, while the everything else doesn't work on any port. I have every port from 1-65534 forwarded and my local IP is static (public IP is dynamic but that didn't matter on my old ISP). My router is a TL-WR841N and my modem is a Cisco EPC3008. I've tried putting my IP into the DMZ, plugging the PC straight into the modem, and nothing has worked so far.
Edited by Zolika1351, 15 May 2018 - 05:34 PM.