Double stacked pistons do not work

I'm trying to build a portcullis. Have read and watched about a dozen videos and have determined there may be something wrong with the Minecraft program.

When double stacking a sticky piston and regular piston or two sticky pistons, only one of them open when connected to repeaters and red dust. I have tried every combination and it still does not work. Even the method in the Mojang Medieval Book does not work.

Hopefully this is a known issue.