Lost Items possibly progress when save and exit in the end

I was exploring the end cities..  after find a second one I cleared out one of the end city arms I decided to save and quit for a while.  The end city I had found was quite large and being really new to the game I didn't want to miss anything.  I had already created 2 shulker boxes for storage and filled them both; (2 elytra, 2 dragon heads, tons of blocks etc) as well I had two ender chests in my inventory when I save and exited.

When I logged back in the next time to continue my search I found myself in a single tower structure that was only 2 stories tall not the huge structure I was in the last time I played.  moments later I discovered I lost all my inventory from my exploits except what remained of my inventory that I brought with me.

 

I didn't capture any screens as I didn't know this would happen.  I also didn't see the point in saving one after the fact as it only proved what was there not what I lost.

 

using locate endcity in console yielded results quite far from my location at the 2 story tower (526 blocks away).

 

I will try to recreate this event and take screen shots if I can