I had an issue with my setup today where my server appeared in the
https://fun4all.lt/serverlist/rF2.php list but I wasn't able to see it through my rF2 client. The dedicated server runs on a separate PC and all the ports were OK on the router.
Other people were able to connect OK; just not me.
However, it worked when I enabled the "loopback" option on the router for the configured ports
Now I can see the server through the client software and join the server OK.
Just thought I'd mention this here so that if someone has the same problem they may come across this when they search the forums