Blocks being moved may disappear or duplicate when chunks reload

My flying machines may disappear, partially disappear (pic 2), or duplicate (pic 1) on chunk borders when the game is reloaded. Doesn’t depend on how I quit the game. My farm has 4 sweeping machines independent to each other, and somehow they all reached different chunk borders at the same time, and broke. Happened multiple times ever since last year, but is not guaranteed to appear every time.