Apple 13 does not display incoming calls, but only shows missed messages.

Maybe "Do Not Disturb" mode is turned on. Do not disturb mode of Apple's mobile phone is a mobile phone setting mode that can prevent being disturbed. After the Do Not Disturb mode of Apple's mobile phone is turned on, he can answer the phone, but there is no hint. And the person who dialed your phone heard that the dialed phone was busy. This function can prevent you from being disturbed and not missing the call. Open the phone settings, select the focus, and click Enter. Select the Do Not Disturb mode option, and then click Enter. Turn on the Do Not Disturb mode switch after setting the Do Not Disturb mode time period, the notification allowed to be received, etc.