Can't see my brother's character in MHFU with public server

[Giraiga13]

Hello, everyone. I managed to convince my brother to download PPSSPP on his laptop (Note: we both are using Windows 10 and the version we downloaded was 1.15.2 if i'm not mistaken) so we could play MHFU together.

We first tried out the IP address of my laptop, and it all worked fine. Now, we wanted to try going for online, so we both followed a guide for setting up all requirements for online play such as choosing a public server (socom.cc) and enabling UPnP. Despite all of that, whenever we entered on the same lobby, we never could see our characters in the lobby, even though the online chat that PPSSPP provides works fine.

Is there an additional step that we're missing? Do we have to change something in our laptops' settings? Is it just a common issue when using piblic servers? Either way, i'm very much looking forward for your responses.