It's quite unusual. The issue occurred because you left the screen at maximum brightness for an extended period with the same image displayed. The pixels on these types of screens can get damaged if you leave a high-brightness image on for too long. The Autel drone remote control screen has a brightness of 2000 nits.
I had a similar problem and used an app called "Dead Pixels Test and Fix."
Let it run at a moderate brightness for a few hours. My screen was restored perfectly. Be more careful with your screen in the future.