I Was Playing With Pistons.I went behind the piston and power it .After unpowering I saw my location changed a little bit and I even used F3 to be sure.My Location change for 0.260 blocks.
MC-160462
Pistons Can Push Entities Behind Them for 0.260 Blocks When Unpowering
Resolved
Duplicate
1
(Unassigned)
Confirmed
Normal
Redstone
block, piston, redstone
1.14.4, 19w36a, 19w37a, 19w39a, 19w42a, 19w45b
Retrieved
This is actually a bug.
But that is a bug from 1.3.
People use this bug for Redstone machines etc.