I found 3 types of piston circuits that do not work, but it's easier to search them on YouTube than it is for me to try to explain them. Mumbo Jumbo is the best person to look for. The circuits are Double Piston Extenders, Redstone Torch Keys, and T-Flip Flops.

I'll try to explain what each circuit is, but I still recommend searching YouTube, as there's more than 1 way to build each type of each circuit. I'll provide links to tutorials of each circuit type.
A Redstone Torch Key lets you place either a redstone torch or redstone dust on a block to activate a circuit. When activated, the key will be destroyed by means of a piston, while also activating a separate circuit. https://youtu.be/zhg67kberPw
Double Piston Extenders are pretty much self explanitory. It fires 2 sticky pistons to push a block 2 blocks forward when powered. When turned off, it retracts both pistons as well as the attached block. The issue here is that the redstone fires too quickly to properly retract both pistons and the block back to their original positions. https://youtu.be/R30ACyF8NHM
A T-Flip Flop turns almost any circuit into a lever. In a piston-powered T-Flip Flop, a sticky piston is given a 1 tick pulse. It pushes and retracts so fast that it does not pull the block back with it. But when powered again, it does pull said block back. A piston T-Flip Flop is commonly used alongside a Torch Key, as that circuit actually does give off a 1 tick pulse. https://youtu.be/9nEWPCSRxOI
The last YouTube link features 2 circuit types: the Monostable Circuit, and the T-Flip Flop. The Monostable is covered in the first half of the video, and does work as it should. But the piston T-Flip Flop covered is only 1 of many versions of that particular circuit.