pistons can't move honey blocks.

Pistons will  not move honey blocks, no matter what redstone signal there is. I connected a direct redstone signal into the back of the piston, facing straight, and pulled a lever. Nothing happened.

I tried with other blocks and this only happened to me with the honey block ( I don't know if it does the same with slime blocks)

The honey block was the only block that was supposed to be pushed, and therefore it did not exceed the 12 block pushing limit.