Greetings, barshechter.
It appears that you're having a problem with the camera on your iPhone 11 Pro Max. Ultra-wide mode won't work but you're able to make a video. We're glad to help with this.
How to back up your iPhone, iPad, and iPod touch - Apple Support -- Please be sure to have a current backup of your iPhone before proceeding.
If you can't update or restore your iPhone, iPad, or iPod touch - Apple Support -- Since you can't delete and reinstall the Camera app, we'd like you to reinstall iOS 14. Place your device in recovery mode using the steps provided. When you're presented with options, please choose "Update" and not "Restore". Once the process has completed, see if the issue has been resolved.
Let us know how that goes.
Take care.