Missing calls on your OnePlus Nord 4 can be a real headache, especially when you're expecting something important. You check your phone and see a missed call notification, but you never heard a sound. The good news is this is usually a simple setting or a minor software hiccup that you can fix yourself.
Let's start with the quickest fix, which solves the problem more often than not. Pull down the notification shade twice to see the full quick settings panel. Look for the bell icon with a slash through it, which is the Silent mode toggle. If it's highlighted, tap it to turn Silent mode off. While you're there, also check that the volume slider is turned up.
Check Your Alert Slider and Volume
The Nord 4 has a physical Alert Slider on the right side, above the power button. This is a hallmark OnePlus feature. Slide it down to the bottom position for Ring mode. The middle position is Vibrate, and the top position is Silent. Make sure it's clicked firmly into the Ring position. Sometimes it can get stuck between settings.
Next, use the volume up button on the left side of the phone to increase the volume while the screen is on and unlocked. This adjusts the media volume. For the ringer, you need to go into settings. Open Settings > Sound & vibration and drag the "Ringtone & notification volume" slider all the way to the right.
Review Do Not Disturb and Focus Modes
OxygenOS has a Do Not Disturb mode that can silence all calls and notifications. Swipe down from the top of the screen to open the notification shade and look for a small moon icon in the status bar at the very top. If you see it, Do Not Disturb is active.
You can turn it off quickly by pulling down the shade twice, tapping the moon tile, or going into Settings > Sound & vibration > Do Not Disturb. Check here for any schedules that might be turning it on automatically at certain times, like during your sleep hours.
Disconnect Bluetooth Accessories
If your Nord 4 is connected to a Bluetooth device like wireless earbuds, a speaker, or your car, incoming call audio might be routed there instead of your phone's speaker. This can make it seem like the phone isn't ringing at all.
Go to Settings > Bluetooth and toggle the main Bluetooth switch off temporarily to test. If the phone rings normally with Bluetooth off, you know the issue is with the connection. You can then go back and manage individual device settings or forget and re-pair the problematic device.
Verify Your Ringtone and App Permissions
Sometimes the specific ringtone file can become corrupted. Try changing it to a different one. Go to Settings > Sound & vibration > Phone ringtone. Select a new tone and have a friend call you to test it. I'd start with one of the default OxygenOS tones to rule out any issue with a custom file you downloaded.
Also, check the permissions for your Phone app. Go to Settings > Apps > Phone app (it might just be called "Phone") > Notifications. Make sure notifications are turned on and set to "Alerting" with sound enabled. Some aggressive battery optimization settings in OxygenOS can sometimes mute app notifications.
Look at Call Blocking and Forwarding Settings
You might have accidentally blocked a number, or a system-wide setting is silencing unknown callers. Open your Phone app, tap the three-dot menu in the top right, and go to Settings > Blocked numbers. Review the list to make sure the caller isn't there.
Also, check for call forwarding. In the same Phone app settings menu, look for Call forwarding. Ensure all forwarding options (like when busy or unanswered) are set to "Turn off" or your carrier's default deactivation code. An active forward sends calls straight to another number without ringing your Nord 4.
Perform a Software Update and Restart
A simple restart clears out temporary glitches that can affect system sounds. Press and hold the power button, then tap "Restart." If the phone is completely unresponsive, you can force restart it by holding the power button for about 10 seconds until the screen goes black and the OnePlus logo reappears.
After restarting, check for a software update. OnePlus regularly releases updates that fix bugs. Connect to Wi-Fi, then go to Settings > About device > OxygenOS version. Tap the top banner to check for updates. If an update is available, install it. The 100W SuperVOOC charger that came with your phone makes this quick, as you can get a significant battery boost in just a few minutes if needed.
Reset App Preferences or Network Settings
If the issue seems linked to a specific calling app like WhatsApp or Messenger, resetting app preferences can help without deleting your data. This resets notification settings, default apps, and background restrictions. Go to Settings > Apps > Reset app preferences and confirm.
For broader calling issues, especially if you have trouble with regular cellular calls, resetting network settings is a good step. This will erase all Wi-Fi passwords, Bluetooth pairings, and mobile network settings. Go to Settings > Additional settings > Back up and reset > Reset phone > Reset network settings.
Check for Contact-Specific Silent Settings
In OxygenOS, you can set custom ringtones or even silence notifications for individual contacts. Open your Phone app, go to the Contacts tab, and select a contact you're having issues with. Tap "Edit" and look at the ringtone option. Make sure it's set to a tone and not to "None" or "Silent."