We first launched Unravel 2 under one account on the PS4 and when playing there I have no trouble playing two player mode. However, when launching Unravel under another account (one of the kids accounts) we can not get player two to join the game. It sais press any key to join, but no matter what we do, one of the controls just seam to be dead. Any ideas? Am I missing something fundamental? Not super familiar with the PS universe...
Are you still having trouble with this?
I'd try a basic power cycle first to see if that clears this up.
If that doesn't do the trick make sure that you have your PSN account activated as the primary on your console so your kids can use the content.
Hope that helps, good luck!