Expected functions:
1. Flip leaver and piston changes state.
2. Flip again and piston changes state again.

Actual function:
1. Flip leaver and nothing happens. Fig. 1
2. Place block on upwards facing piston and it changes state. Fig. 2
3. Remove the block and piston stays the same. Fig. 3
4. Flip leaver and piston changes state again. Fig. 4
5. Same as step one.