If you are using Windows 10 Professional there is a built in vpn server into it. In recent years and months there has been a lot of problem with it. That issue is that computer connecting to the server computer do not make the connection. The problem seems to be in many cases that Windows 10 Pro for some reason does not allocate IP addresses to the computer that is connecting to the vpn server. The solution is simple. That is to create a IP address space on the vpn server in the IPv4 protocol settings (incoming connection -> Protocols -> IPv4). Once that is done all computers connecting to the vpn server should do so without any issues.