How to remove black box when typing on iPhone 17 Pro Max?

Hi there

Please try and force restart the iPhone to see if the issues persist. If they persist, please try this

1. Turn Off "Zoom Controller" or Window Zoom

Sometimes the screen magnifier creates an outline or a floating controller box right where you type.

1. Open the settings app and go to Accessibility.
2. Tap on Zoom.
3. If Zoom is on, toggle it Off.
4. If you want to keep Zoom on but remove the box, tap Zoom Controller and turn off Show Controller.

2. Disable "Switch Control"

If a black or blue box is jumping around your keyboard and selecting keys automatically, Switch Control is active. 

1. Go to Settings > Accessibility.
2. Scroll down and tap Switch Control.
3. Toggle the switch to Off.