Dying after exiting world in MCPE

Hello mojang team! 

For 2 months I was faced with a problem in which I died when I left my world. I don't understand at all how it works and why ... For this is how I have already lost 40 netherite picks ..

I'll repeat you in more detail. When leaving my world, I did not die for obvious reasons. Even when completely closed from mobs, when I left, I was dying of an incomprehensible force.