Three of us tried to host a private server but none of us could join each other because it says "Connect timed out". All three of us port forwarded and we still aren't sure why it does not work. Attached Image: Friend's port forward settings.

You only need to do port forwarding on the computer that is running the server, not all of you.

I don't know if it's the cause of your issue or not, but my router will choke if I put ranges in to the port-forwarding - I have to list every port in its own rule separately to the others.

Quote from Racon :

You only need to do port forwarding on the computer that is running the server, not all of you.

I don't know if it's the cause of your issue or not, but my router will choke if I put ranges in to the port-forwarding - I have to list every port in its own rule separately to the others.

Yes I know that only the computer hosting has to port forward, I mentioned that because all three of us tried hosting and it did not work

It might be a long shot, but besides forwarding ports on router, did you also do that in your computers firewall configuration (if you have any firewall/antivirus software installed)?