When this happens, the user is unable to answer the calls for up to ten seconds according to some reports. This means the phone starts to ring and before the user can answer it, the person on the other end has hung up. Apple discussion threads have hundreds of users complaining about the issue.
User Rakeshvma wrote on the Apple support forums:
When ever i receive an incoming call in my iphone x , ringtones starts but the display come sin after 6-8 seconds . When ever i restart my iphone x the problems gets automatically solved and after 15-20 calls the same problem starts again. I have performed the hard reset as well as the soft reset of my iphone x but it was of no use. Kindly help
On that discussion post, there are over 800 people that have hit the "I have this question too" button indicating they have the same issue. People are reporting that they have done hard resets and the issue persists. Reports also indicate that for at least some, a restore will fix the issue for a couple days and then the same problem returns.
Apple has confirmed that it is looking into the reports but as of now, there is no fix listed. It's unclear if this is a software or hardware issue, although a software issue would make more sense considering that the incoming call bug has only now been widely publicized. Bugs like the "CracklingGate" issue with cracking heard in the speaker and the questionable security of Face ID have been known about for months.