I am not sure if anyone discovered this, but I have a workaround that works for me. When I am at the character selection, before I enter the game, I go into settings, select game, and select the cross-platform action. Then I back out to the character selection and now I can hit L3 and the second player is added. It is late and I am tired, so maybe I actually went one more step on the cross-platform thing. I tested this five times and in each time I was successful.
If no one can follow these steps on the PS4, I can check in the morning when I can go step-by-step on the workaround.
I am not sure if anyone discovered this, but I have a workaround that works for me. When I am at the character selection, before I enter the game, I go into settings, select game, and select the cross-platform action. Then I back out to the character selection and now I can hit L3 and the second player is added. It is late and I am tired, so maybe I actually went one more step on the cross-platform thing. I tested this five times and in each time I was successful.
If no one can follow these steps on the PS4, I can check in the morning when I can go step-by-step on the workaround.