Items Gone after being killed

i was on my survival snapshot world when I got shot by a skeleton. When I respawned, I went back to collect my things and nothing was there, not even XP. I then collected more materials and then I died again. I went back to the same place I had previously died at and my stuff was there.

How to do it:

1. collect items in Survival mode and then get killed by mob or other.
2. Go back to where you died and items will not be there
3. Die again
4. go back to previous death spot (first one) and then items will be there to collect