AFFECTS 1.18.31 Bedrock - Nintendo Switch
When playing on my realm, I have constantly been unable to close the setting menu after opening it after I change the difficulty. Most prominent changes are from peaceful to hard mode, and it has caused my game, on multiple occasions to freak out and stop working , forcing me to save and quit the world. 

To replicate this, here are the following steps I took:

Step 1: Open the Settings menu when playing online in a Realm 

Step 2: Being the admin/host of the server, change the difficulty from Hard to Peaceful (or vice versa)

Step 3: Try and close the setting menu and return the normal game after the change and you should experience the same issue.

Observed Results: unable to exit the settings menu when the B/Cancel/Exit button is pressed on any controller being used. The game with close the menu screen at random after a long pause. 

Expected Results: change any setting or difficulty setting, and be able to exit the menu fully and continue to play the game normally.

I am using a GameCube Controller for this but I get the same results regardless of the controller for the Nintendo Switch. I spam press B or cancel to leave and the game refuses to respond but still allows free roam of the settings and options. The game will have a long pause before finally deciding to exit the settings. 

I have included some images and a quick video of me changing the difficulty in-game, after trying to exit the menu with no response.