When Xiaomi suddenly stops accepting incoming calls or blocks outgoing ones, it can be taken by surprise at the most inopportune moment. Most often, the problem lies not in a hardware breakdown, but in a software failure of settings or activated spam protection functions. Users often confuse operator lock and system limitations of the MIUI or HyperOS shell. The first thing to determine the nature of the restriction is whether the phone blocks the call itself, or the signal does not pass through the network.
This requires a consistent approach, from checking simple "Do Not Disturb" settings to resetting network settings. It's less common for Redmi and Poco device owners, but the algorithm is the same for them. It's important not to panic and methodically check each item, because accidentally tapping or updating the system could change the configuration.
In this article, we will discuss all possible blocking scenarios and provide clear instructions for their elimination. SIM-In 90% of cases, the problem is solved by switching the network mode or clearing the cache of the Phone application without losing personal data. Follow the steps carefully to restore full functionality of the communication.
Diagnostics of the “Do Not Disturb” regime and system limitations
The most common reason that callers hear beeps and the smartphone screen doesn't light up is the activated Do Not Disturb mode. In the MIUI shell, this mode has advanced settings that can automatically turn on schedule or under certain conditions. Check the top notification curtain: if there's a moon icon on, the mode is active. Click on it to deactivate, or go to settings for detailed check.
Go to Settings → Sound and Vibration → Don’t disturb. Here, it is important to pay attention to the item “Repeat Calls”. If this option is turned off, then a second call from the same subscriber will also be blocked within 3 minutes.
- 🌙 Open the Do Not Disturb mode settings and check active schedules.
- 📞 Make sure that the exceptions don’t include the “Favourites Only” restriction if you’re waiting for calls from everyone.
- 🔔 Check if the “Block Notifications” option is enabled at the same time as the sound.
Sometimes a system failure causes the phone to stick in silence even after it's turned off, which can be done by simply restarting the device, and it's also worth checking if Pocket Mode is activated, which can lock the screen and buttons during a call if the proximity sensor is contaminated or covered with a case.
⚠️ Note: Do Not Disturb mode can be activated automatically when you connect to a specific Wi-Fi or when you set your phone to charge.
If the mode is turned off but the problem persists, we move to deeper telephony settings, and users often forget that they have activated locking all unknown numbers in an attempt to escape spam, and now they can not accept a call from a courier or colleague from a new SIM card.
Managing blacklist and blocking of unknown numbers
Xiaomi’s built-in antivirus and security app have a powerful call filtering module. This is where the reason for blocking is most often hidden. Go to the Security → Antivirus → Blacklist (or call settings) app. This displays all the numbers that have been locked manually or automatically by rules.
Pay special attention to the tab "Block Unknown": if there is a switch "Block Hidden Numbers" or "Block All Unknown Numbers", then any calls from numbers that are not in your phone book will be rejected silently, this is a common reason for complaints that "the phone is not ringing."
To clean the list, follow the following steps:
- 🚫 Open the Security app and go to the Lock section.
- 🗑️ Click on the gear icon or the “Blocking History” menu».
- ✅ Select a number and click “Unblock” or use the “Clear All” button».
There is also a feature called “Keyword Blocking” in SMS, which sometimes affects the processing of calls from certain subscribers if they are marked as spam by the antivirus database. Check the antivirus settings and turn off aggressive filtering if you do not need it.
☑️ Checking the blacklist
Settings SIM-operator's maps and limitations
Blocking can occur at the level of the operator or due to incorrect settings of the SIM-If you see a message "Calls are limited" or "Emergency Calls Only", the problem may be in the balance, expired service or blocking by the provider.
Check the network settings in the Settings section → SIM-maps and mobile networks. Make sure that the SIM-Sometimes after the system update, the network settings get lost and the phone tries to make calls via VoLTE or 4G where it is not supported by the operator.
| Symptoms. | Possible cause | Action. |
|---|---|---|
| "Not online" at the subscriber's | Blocking by the operator | Check balance and services |
| Blows and resets | Blacklist on the phone | Check the Security App |
| Only emergency. | No registration on the network | Re-select the network manually |
| Always busy. | Redirection | Reset code forwarding |
| The horns and the horns go off. | Do Not Disturb mode | Turn off the notification curtain |
| Blocking message | Parental control | Check Family Link or Analogues |
Try to get it out. SIM-If you have a dual-sim phone, you can switch priority. SIM for calling to another card in the settings, this will help to determine whether the problem is related to a particular slot or a specific operator.
⚠️ Note: If you have transferred a number from another operator (MNP), Blocking outgoing calls can last up to 24 hours after activation of a new one SIM. You just have to wait for database updates.
Resetting call settings and the phone application
Software errors in the caller application often lead to incorrect processing of incoming signals. The application cache may overflow or become corrupted. To fix this without deleting the call history, you need to clear the application data. Go to Settings → Applications → All applications → Phone (or Calls).
Click on Clear and select Clear All or Clear Data. Don't worry, contacts won't be deleted because they're stored separately in the system or the cloud, and only the configuration of the caller app itself will reset, which often solves the problem of the interface freeze when the call is in.
It’s also worth checking if there are third-party calling apps (like Google or Truecaller) that could have intercepted the rights of the main application.In the default settings, make sure that the standard MIUI/HyperOS app is selected to make calls if you’re not using the alternatives knowingly.
Hidden codes for resetting redirects
Another effective method is resetting network settings, which will bring APN, Bluetooth and Wi-Fi settings back to factory values, but will not affect your photos and contacts. Way: Settings → Connection and Sharing → Reset Wi-Fi, mobile networks and Bluetooth.
Use of engineering menu and resetting the network
For advanced users, you can log in to the engineering menu, where you can force the network type to change. Sometimes the phone gets stuck in 3G or 2G mode, where the quality of communication is unstable, which is perceived as a lock. Enter the dialer code ##4636##. If the menu opens, select Phone Information.
In the "Configure preferred network type" option, select the option that contains LTE/TD-SCDMA/GSM or simply LTE Preferred. Avoid "GSM only" modes if your carrier does not only support 2G. Once you change the setting, the phone may briefly lose the network - this is normal.
- 📡 Enter the code ##4636## in the call app.
- 📱 Select a SIM card in the list of “Phone 1” or “Phone 2».
- 🔄 Change the network type to «LTE/3G/2G (auto connect)».
If the engineering menu doesn’t open (some firmware has blocked the code), use the standard network reset via the menu described above, which often solves problems with registering on the network after traveling to another region.
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Before you change the settings in the engineering menu, take a screenshot of the current values, which will quickly return everything as it was if the connection becomes worse.
Solving screen locking problems during a conversation
A separate type of "lock" is when the screen goes out during a conversation and does not respond to touches, not allowing you to press speaker or complete a call. This is the responsibility of the proximity sensor. On Xiaomi, it is often calibrated incorrectly, especially if you have a protective glass or a tight case on.
To calibrate, type the code ##64663## (or look in the menu "Advanced settings" → "Calibration of sensors"). Follow the instructions on the screen: close the top of the phone with your hand, then remove it. The system will determine the boundaries of the sensor.
Also in the call settings is the "Draw-up Sensor," and try turning it off temporarily to see if the problem goes away, and if the screen stops going out at all, it's the sensor or the software processing.
⚠️ Warning: Do not use magnetic holders for the car in the area of the upper end of the smartphone. Magnets can operate the Hall sensor and approach, causing a false lock screen.
If calibration doesn’t work, try removing the case and wipe the top of the screen. In rare cases, disabling the “Increased Dial in Pocket” option in lock settings helps, if such a feature is present in your version of MIUI.
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Comprehensive check of Do Not Disturb settings, blacklisting and sensor calibration solve 95% of the problems with blocking calls on Xiaomi without the need for flashing.