Portfowarding not working even though it is set up correctly

I have a portfoward setup for a gaming server on port 25565. Occaisionally, the portfoward stops working even though the server is still running and the portfoward still exists, and I have no idea why. Eventually, it fixes itself after some amount of hours and then continues to work.

I've tried restarting my xFi, both by unplugging and doing the online manual restart. I've also tried deleting and recreating the port, in addition to stopping and starting the server up again, yet to no avail. This server is a Minecraft java server, meaning it uses Java. I've heard that some issues can be caused by Windows Firewall, so I made sure that all aspects of Java are let through my firewall, yet I still have this problem.