A number of iPhone X owners have been experiencing delays while receiving incoming calls. They report that the display on the handset can take as much as up to 10 seconds to turn on after the phone initially starts rining.
Some users even report that the display can take more than 10 seconds to wake up which leads to them missing the call as they cannot press the Accept or Decline buttons. Some users are also reporting that the proximity sensor does not work for them properly while they are on a call, with the display failing to turn on when the phone is removed from one’s ears during the call. The issue seems to be present right from the time the iPhone X was first launched, and it is also present under iOS 11.2.5.
Apple has confirmed that it is looking into the issue, though it failed to give a timeframe as to when users should expect a fix to be out. Its unclear at this point if this is a hardware or a software issue. Some affected iPhone X users were given a replacement unit by Apple and the problem persisted on them which likely points to it being an underlying software problem. I have faced a similar issue on my iPhone 7 previously, though the delay was nowhere near as much as 10 seconds. Given that Apple is investigating the matter, it should be a matter of time before the company gets around to fixing it.
The iPhone X has been plagued with multiple issues since launch that Apple has steadily fixed through constant software updates.The Financial Times]