(SOLVED) RUST server - UDP port established, TCP port not to be seen???

[Mr. Analog]

I've been trying to set up a RUST server and, frustratingly, I have no way of being sure that anything is listening on the TCP port, external sites show it as closed, the client sees it on the list of community servers but doesn't allow you to connect. Strangely I can connect to it directly using client.connect with the LAN IP (I played for like 3 hours), but I have checked and re-checked and checked again that the ports are forwarded through the routers port forwarding feature... for a sanity check I tested my Plex port and that shows up just fine. It's like the server just does not connect to TCP.

1. ENSURED windows firewall was not blocking the application(s)
2. ENSURED firewall port forwarding is set up
3. Run netstat -a shows UDP port 0.0.0.0:28015 (perfect) NO entry for TCP (same port)
4. HAVE CHECKED TO MAKE SURE NOTHING ELSE USES THAT PORT
5. Changed the port
6. Changed the server
7. Rebooted everything, repeatedly

I'm out of ideas!

If it helps I'm running an ASUS RT-AC56U

[Mr. Analog]

I reconfigured my router to open the following ports as per this guide:
https://support.steampowered.com/kb_article.php?ref=8571-GLVN-8711&l=english

Then I changed RUST to use port 27015

BINGO