Windows Firewall is a program included with Windows that uses rules to control incoming and outgoing network traffic. It helps to protect your home network and keep your data secure from network threats.
Try to temporarily turn off the Windows Firewall and then make MobileSync connection again. If the connection attempt works, it is Windows Firewall which blocks the connection between MobileSync Station in Windows and MobileSync App in Android.
You can manually add new Inbound Rule in Windows Firewall to allow incoming connection request from MobileSync App in Android devices.
Follow below steps to add a new Inbound Rule in Windows Firewall