The issue I had with the chest was it already became visible to me, but then became invisible later as I followed the path to it. My guess is you placed a tile radius check, but I would suggest to turn it off once the player has discovered by being close enough to it.
In my opinion, it was not just "dopamine rush" and getting "fun" within 10 seconds, but the game currently doesnt have any clear objective for players to work towards. For example, a maze can have an exit but for some reason is locked at the beginning. Then players will be curious of how to get the door to open then will naturally start roaming around the maze.