Read these support guides:
Use Touch ID on iPhone and iPad - Apple Support
or
Get help with Touch ID on your iPhone or iPad - Apple Support
If nothings helps, have your iphone inspected at the nearest Apple Store.
Regards
Giulio
Apple Event: May 7th at 7 am PT
Read these support guides:
Use Touch ID on iPhone and iPad - Apple Support
or
Get help with Touch ID on your iPhone or iPad - Apple Support
If nothings helps, have your iphone inspected at the nearest Apple Store.
Regards
Giulio
Sorry, I've confused touch screen with touch id (my previous answer was not for you).
If you have this kind of problem, try a forced restart of your device with the following steps:
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 Apple logo.
If nothing helps, since your device is brand new, contact your nearest Apple Store and have your iPX inspected.
Regards
Giulio
my iphone x touch works on its own sometimes why?