When your POCO F6 suddenly stops ringing for incoming calls, it can leave you feeling disconnected. This is a common issue with Android phones, especially on newer HyperOS builds, and it's usually something you can fix yourself without too much hassle.
I'd start with the simplest check. Pull down the notification shade twice to see the full Quick Settings panel. Make sure the Airplane Mode icon isn't highlighted. If it is, tap it to turn it off. If it wasn't on, try toggling it on for a few seconds and then off again, this can sometimes give the radio a quick reset.
Restart Your POCO F6
A simple restart clears out temporary software glitches that might be blocking calls. Just press and hold the power button until the power menu appears, then tap "Restart." If your screen is frozen and you can't access the menu, you'll need to force restart it.
To force restart, press and hold the power button for about 15 seconds. Keep holding it even after you feel a vibration. The screen will go black and the POCO logo will appear, signaling the phone is rebooting. This is a safe first step for many weird issues.
Check Your Do Not Disturb and Focus Modes
HyperOS has several ways to silence calls that are easy to enable by accident. Swipe down and check for a crescent moon or a "Focus" icon in your quick settings. Tap it to disable it. For a deeper look, go to Settings > Sound & vibration > Do Not Disturb.
Make sure Do Not Disturb is turned off. Also, look at the rules underneath. You might have a schedule set or a rule that blocks all calls except from favorites. Tap into "Calls & notifications" within the DND settings to see exactly what's being restricted.
Inspect Your Call Blocking Settings
The POCO F6's phone app can automatically filter calls. Open your Phone app, tap the three-dot menu in the top right, and go to Settings > Blocked numbers. See if any numbers you're expecting calls from are listed here by mistake.
Also, go back to the main Phone app settings and look for Caller ID & spam. If this is enabled, it might be overly aggressive. You can try turning off "See caller & spam ID" temporarily to see if it stops blocking legitimate calls.
Verify Call Forwarding is Off
If call forwarding is active, your calls are being sent to another number before your phone can even ring. To check, open the Phone app, tap the menu (three dots), and go to Settings > Call forwarding.
You'll see options for different scenarios like when busy, unanswered, or unreachable. Make sure each one is set to your carrier's default, which is usually something like "Turn off" or "Use carrier default." If anything is set to forward to a specific number, change it back.
Examine Your SIM Card and Network
First, look at the signal bars in your status bar. If you have no signal or an "X" icon, that's your problem. Try moving to a location with better coverage. If the signal looks fine, the SIM card itself might be the issue.
Power off your phone and use the SIM ejector tool to pop out the tray. Take out the SIM card, gently wipe the gold contacts with a soft, dry cloth, and reinsert it carefully. Make sure the tray clicks fully back into place. If you have another phone handy, testing your SIM card in it can tell you if the problem is with the card or your POCO F6.
Reset Your Network Settings
This is a more thorough step that can fix deeper connection problems. It will erase all your saved Wi-Fi passwords, Bluetooth pairings, and mobile network configurations, so be prepared to re-enter those.
Go to Settings > Additional settings > Backup & reset > Reset phone > Reset network settings. Tap to confirm. Your phone will reboot. After it comes back on, you'll need to reconnect to Wi-Fi and your mobile network should re-register automatically.
Clear the Phone App's Cache and Data
Sometimes the Phone app itself gets bogged down with corrupted data. This won't delete your call history or contacts, but it will reset the app's settings. Go to Settings > Apps > Manage apps.
Find and tap on the "Phone" app in the list. Then, go to Storage usage > Clear data. You'll see an option to "Clear all data." Tap it. This resets the app to its default state. After doing this, restart your phone once more.
Check for a System Software Update
Xiaomi and POCO frequently release updates that fix bugs, including ones related to calling. An outdated HyperOS build could be the root cause. Go to Settings > About phone > HyperOS version.
Tap on "Check for updates." If an update is available, download and install it. Make sure your phone is connected to Wi-Fi and has at least a 50% charge, or better yet, plug in the included 90W charger while it updates.
Review Third-Party App Permissions
An app you recently installed could be interfering with call functions. Think about any call recorder, dialer, or security apps you've added. Go to Settings > Apps > Manage apps and look at recently installed apps.
You can try uninstalling suspicious apps one by one to test. Also, check for apps with call-related permissions. Go to Settings > Privacy protection > Permission manager > Phone. See which apps have permission and revoke it for any that don't absolutely need it to function.
If you've switched from the default POCO launcher to a third-party one to avoid ads, that's generally fine and shouldn't affect calls. The issue is more likely with utility or system-helper apps.
Perform a Factory Reset
This is your last resort before considering hardware. A factory reset will wipe your phone completely back to its out-of-the-box state. You must back up everything important first, photos, messages, and app data.
Once backed up, go to Settings > Additional settings > Backup & reset > Erase all data (factory reset). You'll be asked to enter your screen lock password. Follow the prompts to confirm. After the reset, set up the phone as new without restoring a backup immediately to see if calls work on a clean system.