Samsung
Allow Calls in Do Not Disturb auf Samsung
Do Not Disturb on a Samsung phone silences every incoming call by default, including calls from people saved in your contacts.
This happens because the Calls, messages and conversations section inside Do Not Disturb treats phone calls the same way as regular notifications, unless you set an exception.
To change this, open Settings ➔ Notifications ➔ Do not disturb ➔ Calls, messages and conversations ➔ Calls. There you pick between All, Contacts only, Favorite contacts only or None.
All lets every incoming call ring through, useful if you rely on your phone for urgent matters even during focus time. Contacts only limits ringing to numbers saved in your address book, filtering out spam and unknown callers. Favorite contacts only narrows this further to people you have specifically marked as favorites, so only your closest contacts reach you. None keeps Do Not Disturb strict and blocks every call regardless of sender.
This setting only affects calls. Messages and conversation notifications are configured separately in the same Do Not Disturb menu, so check those too if you also want certain texts to come through.