Is device not working properly if it’s unknown

Hi Vanvan21,

Welcome to Apple Support Communities. We see you came to Apple Support Communities from this article: About genuine iPhone displays - Apple Support

Your iPhone may be working fine at this time, but there’s a greater chance it could stop working as expected. From About genuine iPhone displays - Apple Support

The iPhone display is engineered together with iOS software for optimal performance and quality. A nongenuine display might cause compatibility or performance issues. For example, an issue might arise after an iOS software update that contains display updates.

If a service provider uses nongenuine display parts, the following might also occur:

Multi-Touch issues

* Multi-Touch might not respond on parts of the screen

* Degraded Multi-Touch performance, such as missed screen touches or touches not registering in the right location

* Touches might unexpectedly register during a phone call

* Display might not turn off during phone calls

* Accidental edge or palm touches might register

Display brightness and color issues

* True Tone display doesn't function correctly

* Lost or degraded function of the ambient light sensor, causing the screen to dim or brighten incorrectly

* Incorrect display color calibration, such as the display to appearing too yellow or blue

* Display isn't uniformly bright

* Lower maximum brightness

* Unintentional battery drain

You can also see if other parts of your iPhone have been replaced: iPhone parts and service history - Apple Support

Feel free to get back to us with any questions or problems you may have.

All the best.