When the game is in windowed mode and scaled to a small enough size the "Server Difficulty" field in the online options menu can overlap the Realms Notifications button.

This can occur at the default window size when the application is not in full screen or scaled to the size of the entire screen. This can affect players that open the menu when the game does not take up the entire screen. With the default window size of most operating systems causing the issue it is likely for users with different setups to encounter this issue.

Below I have attached two screenshots showing the game at the default minimized window size in a Windows 10 and Gnome DE setup cause the issue.