There are actually two solutions to this. The first one is to shrink all the boxes then jump until you reach the uppermost one then enlarge that to reach ledge as seen in this gif. The second one is to just shrink the 1st box then enlarge, and then jump all the way to the top. Not sure why it became unreachable since I didn't modify the jump height on the last update (just bug fix for crashes and alternative control inputs). Although some players noted that the jump height varies depending on the browser like in Opera GX where the jump height is super high.
