Dirt 5 Online Racing PS5 Dad, PS4 Son crossplay

When you purchase the ps5 version of Dirt 5 they give you the PS4 Version for free. Which allowed me to play with my son online while playing with others.

I wish I could take all my guest online and have a bigger race crew. I would love to have my family vs my brothers family online if possible.

Even if I had 4 players (local) online on PS5 I would want 4 players (local) on PS4 online as well versus others.