As for ruling out firewall being the culprit the easiest way would be to simply completely disable it for the testing period. Of course don't leave it that way for security reasons, only do it for testing. If it works fine then you know you have to investigate more into this direction, if it still doesn't work you can scratch this off the list.
The ideal setup if you have an application firewall (like most software firewalls, including the one integrated with Windows) would be to allow OBS to listen on any ports and leave the default port 0 configured for Teleport, making Teleport automatically pick a random port.
If you have firewalls where you need to set a specific port configure a port explicitly in Teleport and open that in the firewall. In 99% of setups you only need to configure firewall ports on the side that listens for connections, which in your case would be the Linux streaming PC, e.g. you'd need to set up a port in iptables that Teleport (through OBS) can listen on.
Two things I have recently seen that people have done wrong causing issues like that:
- they picked a port number below 1024 - these are reserved and using them will often cause issues, don't do that
- they tried to connect two different Teleport versions with each other, don't do that, use the same version on both sides (currently that would be 0.6.6)