Class avatars cannot be displayed horizontally.

The lock screen rotation option is turned on.

First, open the settings on the tablet, click General in the settings, and click the first desktop setting function in the list. Find the side switch of the option and turn on the option to lock the screen rotation. If you want a flat screen, press it horizontally. If you want a vertical screen mode, automatically switch the horizontal screen and press it vertically. Open the desktop settings menu and turn on the automatic rotation function.