Network configurations can get corrupted, blocking cellular handshakes at the carrier tower level. Reset Network Settings
Both iOS and Android feature advanced focus modes that silences incoming traffic without notifying the caller. Deactivating iOS Focus Modes how to unblock incoming calls
If you are in a weak coverage area, change your data settings from 5G to LTE/4G to check if voice calls route more reliably. Troubleshooting Checklist Contacts hear "User is busy" Disable Call Barring and check Do Not Disturb settings. Calls go straight to voicemail Turn off Call Forwarding and Silence Unknown Callers . Only specific people can't call Remove them from Blocked Contacts in your phone app. No calls go through at all Execute a Reset Network Settings command. If you want to resolve this, please tell me: What brand and model of smartphone are you using? No calls go through at all Execute a
Go to Settings > Phone > Silence Unknown Callers . Toggle this Off if you want to receive calls from numbers not saved in your contacts. Network configurations can get corrupted
