Save state is unreliable. Regardless of whether I stop and save, or just put phone on standby, or if the phones goes into sleep mode, when I return my position is shifted and I often am in a place I was a while before with the world state rolled back to that point.

Once, I appeared in solid rock and died then facing the mods I'd killed ten minutes earlier. Since loading the Discovery Update, i've had two our three crashes on launch.