When I change the difficulty on my realm to something else my screen would either go black or  my hot bar, health, and hunger doesn't show up on my tv screen and what's supposed to happen is it just changes the difficulty and you can still see everything clear so what you need to do is 

1 fix it where the screen doesn't go completely black or my hot bar doesn't disappear

Keep in mind that the only way for me to fix this myself is by reloading back into the world to fix this

And I can't record a video because I play Minecraft on my tv and not this device

If you want to try this the first thing I did was 

1 I was in a realm 

2 I was in survival mode

3 I change the game mode from peaceful to easyh

4 change it from easy to hard