screeen unresponsive on iphone xs max

If your screen is too sensitive or responds intermittently to touch:

1. Restart your iPhone or iPad.
2. Make sure that your screen is clean and free of any debris or water.
3. Disconnect any Lightning or USB-C accessories. If your screen works after removing an accessory, try using a different outlet, cable, or charger.
4. Remove any cases or screen protectors.

If part of your screen doesn't respond, responds intermittently, or responds even when it's not touched, contact Apple Support. 

Hi, I think you should try to restart your iPhone and see what happens.

If it doesn’t work you should go to an Apple Store for technical support.

On the link below you can find everything you need to know about iPhone touch problems.

If the screen isn't working on your iPhone or iPad - Apple Support