Port Forwarding no longer works on my T3200M

[wireless]

I have a T3200M router and for many months I was hosting a Minecraft server on my computer with the port TCP 25565. Since then it stopped working, and this https://www.yougetsignal.com/tools/open-ports/ says the port is closed, even with the server running. I have tried everything I can think of, I've double-checked and triple-checked that all the settings and numbers are correct, but still no success. Nobody can connect, and the port remains closed.
I've tried

• Changing the server port and testing
• Enabling UPnP
• Restarting the Router
• entering Minecraft's ports in the application section of the control page instead of the port forwarding section

There are probably more things I did that I cant think of right now, having struggled with this for a few hours now, but I really don't know how it could just stop working like this. Any help is appreciated.


More...