Ok good. Here are some other things to check:
Your friends computer is over a year behind on Windows update. (this may not be a problem, but I think they should update to rule it out as a possibility.)
I think your issue is network related. If either of you uses a vpn, that could be a problem. If so, you can enable split tunneling for 7D2D to bypass the vpn.
Or disable it temporarily as a test.
Most oem computers include a lot of bloatware that can interfere with the network. Asus GameFirst is one that is known to mess up 7D2D connections.
Check your applications for any bloatware from Asus, HP, Dell, Razor, or any Lighting/RGB software and remove it. Then reboot and try again.
Do your routers include any built in security apps that may be blocking or filtering traffic? If so, try to add exceptions for the game and/or it's ports.