Can't connect to my friends Private Server

Can someone give me a hand with joining my friends private server?? I’m pretty sure he has set up port forwarding correctly, however i keep getting “connection failed” in game and an error code of 10060 in my BeamMP launch window. We have been trouble shooting all night and I just need someone with a good insight as to what my issue could be. Thanks in advance!

That error code is for a port forwarding issue.
Has your friend also allowed the server through the firewall?
Does he have a CGNAT internet connection? If he does, he cannot host servers as his public IP is actually private for his ISP; he either has to ask his ISP to give him a public ip address or use one of our hosting partners (List of partners on Discord or Server Hosting - BeamMP not too sure which one is the most updated).

He has allowed the server through his firewall and we have no idea if he has a CGNAT internet connection. However I have some more info that may help

Okay so i got an update. He was able to connect to the server through his sons PC (which is in the same house on the same network) and also his brother was able to connect with no issues (same internet provider) . I am still unable to connect and I have made sure that BeamMP and BeamNG are allowed in the “Inbound Rules” in my “Windows Defender Firewall with Advanced Security” Would it be an issue with my internet provider?? or his?? Does he possibly need to call his provider and ask for a Public IP Address?? I would be leaning more towards that, but it makes me uncertain since his brother was able to connect and they are not on the same network, just the same provider. Thanks in advance!

What happens if you try to host a server? Can your friend join?

We have not tried that. His internet is much better for the server since he has fiber. He also changed the server to public and I was able to get in no problem. There’s something about when he makes the server private. We just can’t seem to get it to work