Mac mini can't find ATEM video switcher on a managed Ubiquiti Switch

Mac Mini M4Pro. Software for video switcher says it can't find the ATEM but settings-network sees it and says it's connected. Unplug USBc thunderbolt from switcher USBc, settings-network says it is not connected but now the software can see it and address it. I have no clue why this happens or how to fix it. Running MacOS 15.x.

[Re-Titled by Moderator]