Lan or local IPs but not working

[PrinceShalan]

I have two pcs in the same router and they suppose to connect with each other no problem but I faced a weird problem just showing joining session and then the sign just goes away. I thought maybe because of the UPnP not enabled and I do not know how to make enabled so I used hamachi and it worked the UPnP but even with Hamachi the two pcs that are in the same network and in the same wi fi could not go in a game together. I am really struggling to find this problem and find solution because I cant understand what is the problem