Changing the difficulty using commands does not update its corresponding button in the World Options screen

When changing the difficulty using the /difficulty command, the “Difficulty” button in the World Options menu does not update.

The following reproduction steps assumes if the difficulty button is set to “Normal” option.

Steps to reproduce:

1. Enable the LAN option.

2. Place a command block and place the following command into the command block:

   /difficulty easy

3. Have someone activate the command block while you’re on the “World Options” screen.

Observed results:

The button does not update from “Normal” to “Easy”. You have to exit from the screen and re-enter for the button to update.

Expected results:

The button updates from “Normal” to “Easy” while you’re in the screen.