First: No this is not a BUD it is indeed a BUG

When placing pistons like this (first Picture)

When you turn the a Lever on and off again this happens (second Picture)
And yes the bottom one was the lever i pressed.

It also happens in different configurations ,but this is the configuration its easyest to reproduce the bug.

In the second picture you can also see i tested at chunk borders and inside a chunk Both work.

!!BUT!! They height of the structure seems to be important. I built my at "woolheight" 67 and a floor at 64. Cant tell wich of them is important or both.

I hope you can fix this fast cause it can kill a lot of piston contraptions.

To dev: Looks like the piston is not getting updated or is getting updated before the redstone turns off.

To Tester: You have to test around a little bit with positions and redstone length to get it working. I have not found a pattern yet.