There are 5 different achievements - 9 AP in total that you get for doing all of them, and each of them give a chest with minor rewards at the end, which you can only open for about 15 seconds while you have a certain buff on your bar. I'm talking about the achievements, not the chests. Unless the achievement not being completed is a prerequisite for doing the puzzles and opening the chest, I don't see a point for them resetting. Even more so as the chest really isn't any different than those from jumping puzzles, mini dungeons, post-HoT hearts, or even the PoF hero points, which makes it seem like an odd design choice.You don't get the chest if you've already done the puzzle that day, correct. I didn't decide what to put in the chests at the end of the light puzzles, so I can't speak to why they give out what they do, but the chests were always intended to be daily reward chests.