[The Weed]

I'm on Windows. I have no issues connecting to studios, which I have to assume have Mac. Two for sure that I've worked with do have Macs. I got my port: open and set rules in Windows Firewall. AFAIK, those studios also have port: open as that is recommended by Source-Elements. And it's not that difficult, just a few changes in a router.

I've had other voice talent test with me. The "echo" test worked for them and they could hear me, but I could not hear them until they had port: open.

However, if the studio is using "Source-Stream" and Source-Elements says that's Mac only then you are not going to be able to connect with them.

Source- Elements/Source-Connect started life as Mac only and eventually they ported to Windows. However, Windows is still the red headed stepchild and some of their offerings are still Mac only.

It's why I suggested SonoBus as it's free, Mac and PC and Linux as well as iOS and Android and allows multiple connections. Unfortunately, you are unable to use it in this instance and need to find a way to get Source-Connect working for you. Their support is excellent, hopefully they can help. If not and the other end won't try to make changes to connect with you, I'm out of ideas.