I am trying to play this game online with two local users at my PS4. Only one of the users has PSplus (main PS4 account). However, the game will not let the second user join the first user's game in Rocket League. It says the second user needs a PSplus account as well.
My research on PS4 says that multiple accounts can use PSplus as long as the main account has PSplus and the PS4 is registered as the main under his name.
What am I doing wrong?