Bedrock Elevators in 1.17

I have a ps4 and a fire tablet. Thus, I have only ever played in bedrock. I love Redstone, but I find it hard to create anything new. I have been trying for months to find a working elevator tutorial. I have even tried one that was posted on YouTube 20 minutes ago! But I keep running in to one problem. This even happened with the elevator in the Redstone handbook! The flying machine that you use to build the elevator doesn't work! It will fly up three blocks, then the upward facing observer detects that it moved and sends the whole machine back down! The one thing that I want in caves and cliffs part two is either some new way to make an elevator, or for you to fix the old way of making an elevator. Please?