Your private network is probably behind a router/NAT, which means that inbound connections from the internet need to be forwarded from the router to the computer that's running the server. Check your router's manual for "port forwarding".
i recently had a vEthernet (switch) in windows that took my main system ethernet. Xojo couldn't connect untill i set it to off in network adapter settings. Windows will automaticly create a new vEthernet (virtual switch) and it worked.
Or try to see if your sockets have the right NetworkInterface selected. (since i had 2 for example)
Hey. Its just a simple Xojo client/server desktop application (not a web app). The client connects via TCP to the server on port 4900 but I get a server DNR on every call. When I tried this on my AWS server it worked fine with public/static IP addresses but as soon as I put it on the local private network it would not talk to each other using the ip4 address. I opened up 4900 on Windows Firewall with a rule and still no luck. My client is getting frustrated that I cannot figure this out :-(. Both computers are hard wired via Ethernet to the router.