Would exit a world while standing on a chest and when the player would load back in it would cause them to phaze through the chest.

I loaded into the world a while ago while standing on a chest and when I loaded in I was in the floor, I didn't think anything of it, until it happened again, when I was in my sky base with chests in my floor, I logged out and when I joined back in, I phased through the chest again, falling to my death, and losing 42 levels of experience down to now 7 levels.