Vertical flying machine no longer works, which prevents elevator platform build

Vertical flying machines that total six blocks no longer work. I can still build a flying machine that works using 16 total blocks, but can only add two slime and two platform blocks before push limit is reached. This doesn't allow enough coverage to make a platform. I have tried many designs, including my own and can't get anything to work for an elevator that has cap blocks for platform. Only honey and slime blocks, even then they fire randomly to offset and break. Really could use the 6 block flying machine to work again. 

 https://youtu.be/tuXgtad26YQ