Local coop multiplayer is only allowing others to join player 1 approx. 20% of the time.  When it does not work you have to turn off your PS4, turn it back on, go to the game and try again.  The game was a gift to my kids for Christmas, 12/25, and it has been so much fun for them when it works but this is unacceptable.  We have wasted 3 hours doing this over and over till it works.  I've tried finding other updates and even deleting all game data and re-loading with updates but it still has the same issue.