When your Windows device is set to Public Network, the client-server connection may not work. Use the following commands on the device that refuses to connect:
For Server run the command in Command Prompt (as administrator):
netsh advfirewall firewall add rule name="SalesPoint" protocol=TCP dir=in localport=1301 action=allownetsh advfirewall firewall add rule name="SalesPoint" protocol=TCP dir=in localport=1321 action=allow
For Client run the command in Command Prompt (as administrator):
netsh advfirewall firewall add rule name="SalesPoint" protocol=TCP dir=out localport=1301 action=allownetsh advfirewall firewall add rule name="SalesPoint" protocol=TCP dir=out localport=1321 action=allow