After update my back camera is glitching

Hello, Alexandranv.

Let's start off by checking the helpful steps in this article: If the camera or flash on your iPhone, iPad, or iPod touch isn't working. Try these steps:

1. "Remove any case, accessory, or film that might block the camera or flash or that places a magnet near the camera.
2. Test the camera by trying to take a photo.
3. Test the LED flash: Try the flashlight in Control Center on your iPhone or Control Center on your iPad. On an iPhone X or later or an iPad, swipe down from the upper-right corner of the screen. On an iPhone 8 or earlier, swipe up from the bottom edge of any screen. Tap the Flashlight button.
4. If the flash works only sometimes, open the Camera app and tap the flash button to choose a different setting.
5. If the photo is blurry, clean the front and back camera lenses with a microfiber cloth. If you see dirt or debris inside the lens or if the camera lens appears to be misaligned or blocked, contact Apple Support to discuss service options.
6. Restart your iPhone, iPad, or iPod touch. 
7. Test the camera again by taking a photo. If your device has a front and rear camera, check if one or both isn’t working. To switch cameras, tap the rotate button."

In addition, as with all unexpected iPhone behavior, try taking the following steps which may help with the Camera behavior: restart your iPhone, make sure it is up to date, close the Camera app, then reopen it and make sure all apps are updated.

1. Restart your iPhone
2. Update your iPhone, iPad, or iPod touch
3. Close an app on your iPhone or iPod touch
4. How to manually update apps on your Apple device

Let us know if we can help with anything else at all or if this doesn't settle your issue. Thanks and have a fabulous day!