When there is a 1x4 hole in the ground, two filled with water and the other two with waterlogged stairs and an item in the corner the stair is facing; when the water source is taken away from the block next to the stair the item goes up to the stair then drifts back.

Expected:
The item stops at the stairs after the water is removed.

Encountered:
The item drifts back to where it started

Replication:

1. Make a 1x3 hole in the ground
2. fill two with water
3. fill the other two with deepslate stairs
4. waterlog the stairs 
5. throw any item in the empty water in the corner of the half-block of the stair
6. make sure you get it in the corner
7. take a bucket and pick up the water source next to the stairs
8. this does not work every time