APPARENTLY TURNING NETWORK PLAY OFF DOESN’T WORK FOR YOUR FRIENDS. Someone joined my game without my permission and I didn’t see the way to kick them and didn’t get an option to reject them. When I turn off network play that means I do not want to play with anyone including my friends.
But luckily if you turn off your internet on the PS4 you can still completely play the game, and strangely I got this option when I went to the network settings.
Also a quick solution I just found: turn off your PS4’s internet, fully load up the game, and then you can put your PS4 back online and your game will still be offline.