Consider the following simple redstone contraption:
The following can be reproduced in 1.14.* and 19w45b:
If a button above a blue wool is pressed, the piston would extend, but not retract (unless you send a block update by pushing the
reset button). However, if you press a button over an orange wool, then the piston would extend and retract automatically.
Back in 1.5.2, all button press would cause automatic retraction; in 1.10, none would cause automatic retraction.
So my question is, why does the parity (i.e. odd or even) of the redstone wire length affect the behavior of the piston? Shouldn't it be uniform?