Duplication of observers and red stone lamps (Ghost Blocks)

Hi.

When trying to make a slime elevator, I made a mistake and then it started spewing out observers and red stone lamps. I don't know how it is doing it, but I believe it is from the slime block at the front of the machine. If you want to replicate it, I recommend you add the two observers under the piston and the slime block at the end to start the clock.

Thanks, please let me know if you need more information.

(Also it works better between two chunk and works in 1.12.2 pre-release )