I have same expierience that it does not work in IO network. Working perfectly in Public and Private networks. I also could not find anything in manuals about any restrictions. Seams to be bug or feature.
Admittedly this might be a rookie question, but what did you set the DNS and the default gateway to? I’m trying to connect over a machine network, there is no DNS host. Every other device on the network you can just leave those blank. I spoke to support and apparently you cant connect over the IO network, or at least the person reading the manual on the other end of the keyboard thinks that. Feels like a bug to me.