Pistons (or observers, I can’t figure it out) not working like before

Hi,

as soon as I updated Minecraft beta on my Xbox one to version 1.15.0.53, I noticed that my flying machines weren’t working anymore.

here’s the link to the video of the tutorial for said flying machine, please watch before you continue reading:

https://youtu.be/RMHrUXwk2T4

 

as you can see in the video, it works just fine and it did before this update. The sticky piston doesn’t pull the rest of the contraption and I can’t understand if it’s a piston bug or if it is a observer bug. Please fix, my city’s transit mostly depends on these infinitely expandable aircraft.

 

thanks.