Unpushable Slime block

I got into my snapshot world, and i was exited to try out the Sticky Slime Block feature! So, I grabbed a sticky piston, put a slime block next to it, and then when i powered it, i understood the slimy block was unpushable! Pretty much lag free. Java 8. Windows 8.1. By the way, i mean all snapshot versions had this bug. I never crashed. Oh, and sorry i just noticed this is the same as MC-54321