First of all, you seem to be checking for open ports with nmap, which isn't 100% reliable (especially when connecting to the loopback address, which your server might not necessarily bind to) On my rcon-enabled server, the rcon port appears to be closed according to nmap, but works fine. A better way to check is using netstat ("netstat -an" works equally well on windows CMD and *nix-based systems) which should show [::]:25575 as "listening"
Have you tried using the RCON/Query utility to query the server? remember to try both console (25575 by default) and remote query (25565 by default. You've changed yours to 25567, which really shouldn't matter, but you might consider changing it back, just to be sure.)
If you still can't connect, does the console indicate rcon is enabled when you start the server like so:
CONSOLE: Default game type: 0
CONSOLE: RCON running on 0.0.0.0:25575
If so, what happens when you open a telnet session to your servers IP (preferable not the loopback address), port 25575? You should get a hanging blank window (as opposed to a "connection closed"/"connection refused" message) and an entry in the server console along the lines of "Rcon connection from: /127.0.0.1"