Steps to recreate

  1) Place shulker box

  2) Stand next to the shulker box (when standing just a couple blocks away, this bug does not happen)

  3) Have another player stand on the shulker box

  4) Have anyone open that shulker box

I have had this happen 5 times in a row when testing to try and see what exactly the circumstances were for my game freezing and having to hard reset it.