Temporarily disable the virtual WiFi network created by WSA and reconnect to a regular WiFi network. See if the Amazon AppStore works reliably on a standard WiFi connection. If it does, there might be an issue with the virtual network setup.
Check if any firewall or security software on your computer is interfering with the Amazon AppStore's connection. Temporarily disable such software to see if it resolves the issue.
Run the Windows Network Troubleshooter to identify and fix common network problems.
Update Network Drivers