Changing realm settings don't apply when resume game.

I have purchased realm and created a new world in world setting when I'm turning of mob spawn or any other option keys like friendly fire off or on the setting doesn't apply when resume the game I was not facing this issue previously I created new world I even tried on offline mode i uninstalled the game and then reinstalled it again but the issue is still the same , if setting doesn't apply when change , what is the point of giving an option like that . I want mojang to fix this for I have paying 530rs not for glitches or bug