How to reproduce:

1. Build a small structure and add a shulker to it using a shulker spawn egg.
2. Save the structure using a structure block. Make sure to activate "Include entities".
3. Load the structure in at a position that is diffrent from the one where the structure was saved at. Again, make sure to activate "Include entities".
4. The Shulker will instantly teleport to the same x, y and z coordinates it was originally saved on. This will still happen if there is a block at the position the shulker was saved on.