Connection Error on same network

Hi All, been having connection issues when trying to play with my girlfriend.

We are both staying together and playing side by side, meaning we are both on the same network.

Whoever joins first has no issue joining the games but the 2nd one would be unable to join, getting the connection error, bandwidth bla bla bla.

Like to check if there is any way to resolve this? it feels like an IP thing as we are both on the same network.

note: we both own 1 copy of BFV each.

Thanks!