This piston does not retract the slime block at Y level 1 (i checked for connected blocks, but there are no) (I was playing in a world with a friend) Video: https://1drv.ms/v/s!AitQ1Noc9ii72y3Haym_6fm_A1yl?e=0jZWSl
Steps to Reproduce:
1. Create a flat world in creative mode
2. Break the blocks a bit, that the piston cannot push them
3. Break the bedrock
4. Place a piston with a slime block on top at Y level 1
5. Place a leaver and flick it
The Piston pushes the slime block, but when you retrack it, the piston cannot pull the slime block.
The Piston retracts the slime block.