iPhone X ios 11.3 - Landscape - Ambient Light Sensor Malfunctions

Hey stevenejb,
It sounds like you’re having an issue with the ambient light sensor where your display turns on and off repeatedly when you turn the iPhone into landscape mode. I’ll be happy to look into this with you.
First, let's try toggling auto-brightness off and then on again in Settings > Display & Brightness, then restart your iPhone. Test again to see if you still experience the issues with landscape mode.
Do you have a protective case or protective film on your iPhone? If so, we recommend removing them and testing the iPhone again. Because the issue is with the ambient sensor and with the display not responding to touch sometimes, the issue could be with interference.
If the issue persists, I recommend that you reinstall iOS on your device. Before you proceed, please back up your data using the steps below:
How to back up your iPhone, iPad, and iPod touch - Apple Support
Once you've verified that your backup is current, follow the steps below to reinstall iOS on your iPhone. Keep in mind that this article was written for a different issue, but these steps will still be helpful:
If your iPhone, iPad, or iPod touch won't turn on or is frozen - Apple Support
Here’s the steps:

If your device turns on but gets stuck during start up

If you see the Apple logo or a red or blue screen during startup, try these steps:

1. Connect your device to a computer and open iTunes. If you don't have a computer, try to borrow one, or go to an Apple Store or Apple Authorized Service Provider for help.
2. While your device is connected, force it to restart.
   • On an iPhone X, iPhone 8, or iPhone 8 Plus: Press and quickly release the Volume Up button. Press and quickly release the Volume Down button. Then, press and hold the Side button until you see the recovery-mode screen.
   • On an iPhone 7 or iPhone 7 Plus: Press and hold the Side and Volume Down buttons at the same time. Keep holding them until you see the recovery-mode screen.
   • On an iPhone 6s and earlier, iPad, or iPod touch: Press and hold both the Home and the Top (or Side) buttons at the same time. Keep holding them until you see the recovery-mode screen.
3. Don't release the buttons when you see the Apple logo. Keep holding until you see the recovery mode screen.
   
4. When you get the option to restore or update, choose Update. iTunes will try to reinstall iOS without erasing your data.
   

iTunes will download the software for your device. If it takes more than 15 minutes, your device will exit recovery mode and you'll need to repeat steps 2 and 3.

Take care!

Had the same issue, display turning off when the ambient light sensor is covered with your hand in both portrait mode and landscape mode. I fixed the problem by turning off auto-brightness (accessibility settings under display accommodations), restarting the phone, and turning auto-brightness back on. Hope this helps.

There’s no option to turn off auto brightness on the Verizon version of the iPhone 8.

But just shutting down and turning back on fixed it for me. Hope this helps.

Same problem here. Started with last update. Turning phone off and on fixes it temporarily. Please fix asap.

This doesn't do anything. Auto brightness has no effect on this issue it is a iOS bug. It's ever sense 11.3.1 and reinstalling iOS is impractical when our phones are >120GB consumed in storage these days. This bug renders the phone borderline useless which is an issue as this is a work phone. Unacceptable bug, needs to be fixed immediately

I started to experience this issue at random, two days ago. I am not sure what triggered the issue, since I had not updated my phone recently. This was quickly becoming a very frustrating bug since I had to remind myself to operate the phone one handed while doing anything on landscape mode. I followed the instructions provided here and it worked on the second attempt.

Thanks

Same issue here with the sensor.. I don’t have a cover and it just started after the latest update. Apple, please change it back.

Me too. Ever sense 11.3.1 on iPhone X. It's annoying on the camera because I can't take a picture. But I cannot even touch the top to scroll to the top of a page without the screen shutting down.

These steps works for me as well. Thanks!