My Kindle recently updated to the version of MCPE that contains turtles (I think that's 1.5), but I've found as I'm trying to build that I'll place several blocks wait a brief second and then several of the placed blocks disappear. I can place them again, but each time I place several blocks at least part of them have to be redone. This is most frustrating. It has occurred with wood blocks (full, step, and half sizes), stone blocks (full, step, and half sizes), glass (full), and banners.
Likewise, when I destroy blocks, a few seconds later, some of the reappear! (Grass, stone, banners, etc).