Piston Goes Invisible In Automatic Farm

I built a automatic farm on an unmodified world of mine and the piston what i was using to break the pumpkins went invisible and i cant break the block nor can i build where the piston was glitched at, in the picture below it shows where the piston was glitched though i cant get recording of me trying to place a block there, the majority of the pistons still work but the other ones do not the other ones > the invisible pistons