Hello Danimal66, this could be a sign that your router is starting to fail. If you are not having to change the IP address set up for port forward to match a new IP address shown on the FG screen, and it works some times but not others, then I would start suspecting the router.
If the router is just assigning a new IP address and your port forward entry no longer points to your system, then this is something that can easily be fixed by either:
- Extending the TTL setting for DHCP on your server to allow it to keep the same assignment longer
- Checking the IP displayed in FG each time and then make sure the router's port forward still matches. Change on the router if needed
- Set your router to always assign your computer the same IP address.
Edit: Before you replace your router, check to see if there is a firmware update you can run on it and then re-test.