Why the blacklist in the Xiaomi Mi 8 phone doesn’t work

Owners of Xiaomi Mi 8 smartphones often face a situation where the number added to the ignorant list continues to disturb calls or messages. This is puzzling, because the lock function should work automatically and faultlessly. However, there are nuances in the MIUI shell that can prevent the correct operation of call filtering.

The problem can be either software failures of the system itself or incorrect access rights settings or synchronization with cloud services. Sometimes third-party applications or operator features are the culprits. In this article, we will discuss in detail all possible causes and ways to eliminate them.

It is worth considering that the algorithms for working with contacts in different versions of firmware may differ. If you have recently updated or, conversely, have not updated the system for a long time, this can affect the stability of the system modules. The critical factor is often not the fact of adding to the list, but the activation of the corresponding switches in the lock menu.

Features of call filtering in MIUI

Xiaomi’s filtering system is built on the integration of multiple system services, not only the phone book but also a separate security service is responsible for processing incoming connections, and if one component is not working properly, the entire lock mechanism can fail.

MIUI uses dual control: antivirus database check and local list of banned numbers check. The user must make sure that both levels of protection are activated. Often, the number is added to the database, but the "Block" switch for a particular category (for example, "Hidden numbers" or "Advertising") is turned off.

It is important to understand that system constraints can also be imposed on SIM-Some operators provide their Anti-Determinator or Blacklist services, which may conflict with the system settings of the phone, in which case the priority is often given to network settings.

The main reasons for the failure of the lock on Xiaomi Mi 8

There are a number of common errors that make the blacklist no longer function properly, most often the problem is that the security system application does not have the necessary permissions, and without the right to read the call log or control the phone, the application will not be able to intercept the incoming signal.

Another common reason is sync via Mi Cloud. If you added a number on one device but sync on Xiaomi Mi 8 didn't go through or was error-free, the contact won't get into the local lock database.

• 🚫 No updates to the system application "Security" or "Phone".
• 🚫 Conflict with installed third-party calls (such as Truecaller or Google Phone).
• 🚫 Cache of system services responsible for switching.
• 🚫 Incorrect format of recording a number in the lock list (for example, without a country code).

Also worth paying attention to is Do Not Disturb mode, which, if activated, can override blacklist settings or bypass them by skipping calls from favorite contacts, even if they are formally blocked on another menu.

Checking the settings of the application Security

The central element of lock management in Xiaomi is the Security app, which is where all the key switches are located, and you need to open the app and go to the Antispam (or Lock) section.

Inside this menu, check the settings tab (usually the gear in the corner) Make sure the lock switch is active. If it is turned off, no added numbers will work, no matter how many in the list.

Then you have to check the lock rules, and you have the flexibility to adjust the responses to different types of calls, and you can set the lock for all unknown numbers, for numbers from other regions, or only for those who have hidden their ID.

⚠️ Note: If you use a third-party theme, it may hide some interface elements or change the logic of the menu.

Configure the rules of blocking and exclusions

The flexibility of MIUI allows you to create complex filtering scenarios, but this can also be a source of problems, for example, if you have the option "Whitelist" (allow only favorites), then all other calls will be blocked even if they are not on the blacklist.

Check the Exceptions section in your anti-spam settings, and often the contacts you once added to your Favorites or frequently called numbers get in, and the system thinks you want to hear those people anyway.

For the effective operation of the blacklist, it is recommended to use the following settings:

• 📞 Block Hidden Numbers – Enabled.
• 📞 Block numbers not from the phone book - if desired.
• 📞 Blocking by Keywords in SMS — separately tuned.
• 📞 Notification of blocked calls – enabled for control.

You should also pay attention to the Smart Lock feature, which uses Xiaomi databases to identify spam numbers, and if this feature doesn't work, check your Internet connection, as online access is required to check numbers.

💡

For maximum efficiency, enable automatic update of spam databases in the Antispam settings, which will allow you to block new fraud numbers as soon as they appear in the databases.

Third-party application impact and calls

Many Xiaomi Mi 8 users replace the standard call with a Google app or other analogue, which often leads to conflicts. The standard MIUI blacklist is sharpened to the native Phone app. If you use a third-party, the settings may not apply.

If you don't want to give up your favorite call, you'll have to set up a blacklist inside the app itself. Xiaomi's system settings can be ignored. Check which application is the default for making calls.

To check and change the default app, go to Settings → Apps → Application Management → Three dots in the corner → Default apps → Phone. Select the desired app and check its internal lock settings.

⚠️ Note: When using two or more call blocking apps (e.g. built-in and Truecaller), they can "cry out" each other, skipping spam. Leave only one active filter.

Technical solutions and resetting settings

If the software settings are fine but the calls are still coming in, there may have been a system failure, in which case cleaning the cache and data from the Security and Phone app helps, and it won't delete your contacts, but it will reset the filtering settings to factory ones.

To do this, go to Settings → Applications → All apps. Find Security, press Memory and select Clean (or Reset).

As a last resort, if the problem has appeared after the firmware update, you may need to completely reset to factory settings. Before that, be sure to back up all important data.

Also check if you have multiple numbers in contact, and if you block one number and the caller uses a second number saved in the same contact card, the system may miss the call, considering it "familiar."

💡

The most reliable way to block is to use the built-in MIUI tools in conjunction with a standard call and regularly update spam databases.

Frequently Asked Questions (FAQ)