jussius: This problem is extremely complicated for this collection. It's very hard to tell if it's better to start with N8 or J12, or if both are sente so it doesn't matter.
Then there's also the fact that K8 is probably sente now but not after N8 so maybe the sharpest endgame is to start with K8...
Ivan Detkov: The solution is good. Black will be answering at the top and N8 is still in the pocket. It is still not bad to start from N8. I added it as a valid first move.
GoAlphons: A bunch of these problems are called endgame, none of them are endgame with the board wide open. The correct answer in this case is not the best move on the board so it gives people the wrong idea, especially since these are beginner exercises.
TwT: I understand that you may feel frustrated. Would it be helpful to restrict access to the other half of the board as it is currently set up?
The solution is good. Black will be answering at the top and N8 is still in the pocket. It is still not bad to start from N8. I added it as a valid first move.