The issue goes as follows:

• Minecraft freezes for a few seconds, with its sound freezing too. 

• My Xbox One X will turn off and restart as if I would restart it by pressing the power button down for 10 seconds. "Hard reset" or whatever it was called. 

• The issue seems to have appeared now after my Minecraft world is over 100mb, it being around 130-140mb.

I can't really recreate it as it seems to be fully random and can happen in a matter of few minutes of gameplay, or after I have played for a few hours.

I play in my Realm as I had this kind of an issue happen on a local map that went over 200mb, and crashed, after which it could no longer be loaded.

I doubt its caused by my Realm, since it does happen in a world thats local too.

My friend whom plays on Windows 10 doesn't have any crashes. Any clue what could be causing this?