A Canadian YouTuber named Dave2D recently discovered an issue with the iPhone 18 Pro Max's Face ID feature when using a matte screen protector. In his review, he noted that Face ID stopped working reliably with the matte protector, but functioned normally with a standard transparent one. This problem stems from a change in Apple's design for Face ID, which is now embedded under the OLED display panel. Unlike previous models, the iPhone 18 Pro Max no longer has a large black dot on the screen for the infrared camera. Instead, Apple placed the infrared camera and sensor under the screen, leaving only a small hole for the front-facing camera. To allow the Face ID sensor to work through the screen, Apple created a less dense area of pixels in the top-left corner of the display. This area is designed to let infrared light pass through, enabling the sensor to map a user's face. However, matte screen protectors can interfere with this process by scattering the infrared light, making it harder for Face ID to function properly. In contrast, transparent screen protectors allow the infrared light to pass through with minimal disruption. This is the first known issue reported with Apple's under-screen Face ID technology, raising questions about the reliability of the design. To avoid problems, users are advised to use transparent glass protectors instead of matte ones. Some accessory manufacturers are already adjusting their products to ensure the sensor area remains clear. Apple has long warned users to avoid screen protectors that cover the TrueDepth camera, which is essential for Face ID to work correctly. Apple continues to be one of the few major smartphone manufacturers offering 3D facial recognition technology, alongside Honor on its high-end Magic models. As the race for full-screen displays continues, companies are expected to introduce more innovations. For example, Samsung is developing its own facial recognition system, called Polar ID, which is designed to eventually replace Apple's Face ID. These advancements highlight the ongoing competition in the smartphone industry to deliver more seamless and secure biometric authentication methods.