Inaccurate death and spawn

I've been traveling for a while and I was around the coordinates 10000 and -12000. I've slept in multiple undestroyed beds on my journey there. Last time I believe I was crossing a river, I was above the water and had full oxygen. I turned my iPad off to go to sleep and when I logged back on it said that I had drowned and then it spawned me at my original spawn area which are the coordinates 130 and 80.