If you have trouble connecting to a server on your local network, all of the following things are likely interfering with the ability of the apps to make a connection:
- DNS Rebinding Protection: Many routers allow enabling this protection (some enable it by default), but at the moment this can interfere with the ability of the apps to connect to your server.
- NAT Loopback/Remote Access: The apps are capable of connecting via remote access to your local servers as well, but remote access has to be enabled, and your router has to support NAT loopback.
- Require Secure Connections: If your server has this configured value in network settings (as opposed to Preferred) this can also interfere with the ability of the apps to connect.
Note that the apps will only have trouble connecting if all of the above holds true. Changing any one of these items should allow successful connections.
Related Page: How to Use Secure Server Connections