In the SMS interface, you can automatically write handwritten information on the horizontal screen. Am I out?

That's because the phone didn't open the vertical screen lock.

Solution:

Double-click the Home button.

Slide the page at the bottom of the phone to the far right.

You will see a hollow circle with an arrow.

Click on the circle and a small lock will appear inside.

At this time, the mobile phone will not have a horizontal screen.