When a subscriber can’t reach you and a “locked call” appears on the screen, it is often a cause for confusion and anxiety. Owners of Xiaomi, Redmi and Poco smartphones face this more often than others due to the aggressive optimization of MIUI and HyperOS. The problem can lie in both random activation of the “Do not disturb” function, and in deeper system conflicts or operator settings.
Before you panic and bring the device to the service, you need to conduct a thorough diagnostics of the software part. Call blocking is not always a sign of failure, often it is just a malfunction in the standard application "Phone" or an incorrect setting in the security menu, Understanding the nature of the ban will quickly return the connection.
In this article, we will discuss all possible causes of the error and propose specific algorithms for eliminating them. SIM-Maps and system resets that are guaranteed to help solve the problem.
Diagnostics of the causes of blocking calls
The first step should always be to identify the source of the problem accurately, and the lock can occur at the level of the smartphone itself, through operator settings, or even due to physical damage. SIM-If calls are blocked only from certain numbers, it is likely to be a blacklist or spam filter.
In the case of incoming calls are not coming from anyone, and outgoing calls are working normally, it is worth checking the network modes. Sometimes the phone “hangs” in 4G mode only, ignoring incoming 2G/3G if the operator uses VoLTE technologies incorrectly. It is also important to exclude physical contact: try to move the SIM card to another slot or to another phone.
System logs can tell you which application is intercepting the call. Owners of Xiaomi devices should pay attention to third-party applications for determining the number, which may have their own databases of blocked contacts.
- 🔍 Check the lock status of a specific number in the call log.
- 📶 Make sure that data is enabled and voice services are active with the operator.
- 📱 Testing the work with another SIM-Device to eliminate hardware faults.
- ⚙️ Check if the “On the plane” or “Do not disturb” mode is activated».
Set up a blacklist and lock in MIUI
The most common reason is an activated blacklist, and in the MIUI shell and the new HyperOS, the built-in Security app is responsible for that, and if you accidentally add a contact to the banned list or enable the locking of all unknown numbers, the calls will simply not go through, and the caller ID may not even catch fire.
To check the settings, you need to open the Security app (green zipper icon) and go to Lock. This displays all the statistics of blocked events. In the upper right corner there is a settings menu (three dots or gear) where you can control the filtering rules.
⚠️ Note: In some firmware versions, the Block Everything feature can be activated automatically after you update the system or reset your antivirus settings.
You can set exceptions to the lock menu, like allowing calls only from contacts or blocking everyone except a select few, and it also stores a history of blocked SMS and calls, which helps you understand who tried to reach you.
☑️ Checking the blacklist
Do Not Disturb Mode and Sound Profiles
Often users confuse software call lock with silence mode. Do Not Disturb mode on Xiaomi has advanced functionality and can completely reject incoming calls, sending a subscriber a “busy” or reset signal. This mode can be activated on a schedule, for example, at night, and if the time on the phone is knocked down, it may not work properly.
You can check active profiles through the notification panel (curtain). If there is a crescent or star icon on, the mode is active. More subtle settings are available via Settings → Sound and vibration → Do not disturb. Here you can allow repeated calls: if the same person calls twice within 3 minutes, the phone will miss the call.
It's important to distinguish between silent mode and total notification ban. In the first case, the call goes, but the phone is silent. In the second case, the call can be rejected by the system automatically. Also check the sound profile: sometimes in the "No Sound" profile, there is a tick "Block all incoming".
- 🌙 Turn off the "Do Not Disturb" mode via the Quick Access Panel.
- ⏰ Check the schedule of automatic activation of silent mode.
- 🔁 Activate the “Repeat Calls” function for emergency cases.
- 🔊 Make sure the call volume slider is not twisted to zero.
Hidden schedule settings
Impact of the operator and network settings
If the phone settings are in order, the problem may lie on the operator side.The Black List service is often provided by telecom companies (MTS, Beeline, MegaFon, Tele2) and may be activated by accident through USSD-In this case, the lock is at the network level, and the phone does not even receive a signal about an incoming call.
To check, you need to log into the operator's personal account or call support, you should also check if the forwarding is activated, you can reset all redirects with a universal command, sometimes re-registration on the network helps: turn on flight mode for 10-15 seconds and turn it off.
Another important aspect is the type of network. 4G/LTE, Voice calls in your area are going through 2G/3G (If VoLTE is not configured, incoming can be lost. SIM-Select the type of network preferred 4G (LTE) or 3G/2G (test-car.
💡
Use it. USSD-For example, #002# usually cancels all types of forwarding, and *111# (code depends on the operator) opens the menu of blocking services.
The table below contains the main parameters that should be checked by the operator:
| Parameter | Where to find out | Possible solution |
|---|---|---|
| Blacklist | Personal Account / USSD | Clear the list of prohibited |
| Redirection | Call settings | Reset by team ##002# |
| Type of network | Settings SIM-map | Replace to 3G/2G for the test |
| VoLTE | Mobile network settings | Turn on or off for inspection |
Resetting call settings and the phone application
Xiaomi’s Dialer app has its own cache and database, which can get corrupted over time, and this leads to incorrect processing of incoming signals. Cleaning up the data of this app won’t delete your contacts (since they are stored in a separate Google or Mi Account service), but it will reset your call settings to factory ones.
To perform the procedure, go to Settings → Applications → All apps. Find the Phone (blue handset icon) list. Select Clean → Clear Everything (or Reset) and the phone can then restart and the call settings will be updated.
It's also worth checking the permissions for this app. Make sure the Phone has access to the microphone, contacts and, crucially, to display over other windows. Without the last item, the call screen might just not appear, creating the illusion of locking.
⚠️ Warning: After resetting the Phone application, the number and call recording settings may reset. You will need to re-enable the call menu record.
If the problem is not solved, you can try a more radical method, resetting the network settings, which will return the parameters of Wi-Fi, Bluetooth and mobile communication to their original values. Path to function: Settings → Connection and Sharing → Reset Wi-Fi, mobile networks and Bluetooth.
💡
Phone data cleanup is a secure procedure that eliminates 80% of software glitches associated with passing incoming calls.
System conflicts and software updates
Sometimes, third-party applications that intercept calls are the cause of blocking, such as number detectors, call messengers, or memory optimizers, and if a problem occurs after you install new software, try removing it or running your phone in Safe Mode.
In Safe Mode, only system applications are loaded. If this mode is normal, then it is the fault of third-party software. It is also worth checking for system updates. Xiaomi regularly releases security patches that fix the errors of the communication module.
You can check for updates on the Settings → About phone by clicking on the MIUI/HyperOS version. If an update is available, install it. In rare cases, a rollback to the previous firmware version helps, but this requires unlocking the bootloader and having a backup.
- 📲 Remove newly installed number detectors.
- 🛡️ Check your phone with a built-in virus scanner.
- 🔄 Update the system to the latest available version.
- 🧪 Test the work in safe mode.