Unable to determine if your iPhone display is a genuine Apple part. This could be because the part is non-genuine, not functioning as expected, or the installation is incomplete.

All the answers are listed in the support article that led you here.

For any further doubt/question about this matter, please contact Apple Support using this link:--> Get Support, or make an appointment (*) and have your device inspected at an Apple Store or AASP (Apple Authorized Service Provider) among this list:--> Apple – Location Selector. After checking it out, they'll give you all the available options.

Regards

Giulio

(*) You can do it:

• Online:--> Genius Bar Reservation and Apple Support Options - Apple;
• Contacting a local Apple Store or AASP among the list provided above;
• Using the "Apple Store" app, available and downloadable from AppStore.

Has the display been replaced in the past?

What iPhone do you use and which iOS version is installed?

You might have to get the phone checked by visiting an Authorized Apple Service Provider next to your place, in case this is related to a hardware issue.

Use this link to find one:

Apple - Find Locations