Many Xiaomi smartphone owners face an intrusive “Certificate Discovered” notification or problems connecting to Wi-Fi after installing various ad-blocking apps. HTTPS-The trafficker inserts its root certificate into the system, and if you no longer use the application or it was removed incorrectly, the certificate may remain in the device's memory, causing malfunctions in banking programs and system security services.
In Android, which runs the MIUI shell, digital security keys are managed in a separate section, and simply erasing the application from the desktop is not enough — you need to manually go into encryption settings and remove malicious or unnecessary trust profiles, which will return the phone to normal operation and remove persistent warnings from the system.
In this detailed guide, we will look at all possible ways to clean up AdGuard residues from your system. You will learn where to look for hidden certificates, how to proceed if the delete button is inactive, and what to do if standard methods do not help. MIUI HyperOS.
Why AdGuard Certificate Stays in the System
AdGuard is a local proxy, and in order to filter traffic inside other applications (such as a browser or game), it must be able to decrypt and verify. HTTPS-To do this, it puts its root certificate on the list of trusted certification bodies of your device, which allows the application to "see" all the traffic that passes through the phone.
The problem arises when a user deletes the app itself but forgets or fails to delete its system trail. In some cases, especially on Xiaomi smartphones with their aggressive battery optimization, the deletion process can be interrupted, resulting in an entry in the account storage that continues to affect the security of the connection.
⚠️ Warning: Having a third-party root certificate in the system reduces security, and in theory, if that certificate gets into the hands of malicious users, they will be able to intercept your traffic even if you use secure connections.
In addition, many banking applications and government services (such as State Services or Sberbank) can block their work when third-party certificates are detected, considering the device compromised, so removing unnecessary profiles is not just a matter of cleanliness of the system, but also a necessity for the normal operation of fintech.
Search and Remove Through Security Settings
The easiest and safest way to remove a certificate is to use a standard Android interface. The path to the right settings may vary slightly depending on the version of MIUI, but the logic remains the same. You don't need root rights or a computer connection.
First, open the settings menu on your smartphone. Find a section that could be called Password & Security, Security, or Biometrics & Password. That's where the encryption keys are hidden. In some firmware versions, the item you want is at the bottom of the list or hidden in the Privacy submenuum.
The algorithm of actions is as follows:
- 📱 Find the item “Encryption and credentials” (sometimes called “Device Security»).
- 🔐 Select the option “User Account Information” or “Trusted Certificates».
- 🗑️ In the list that opens, find AdGuard (or AdGuard filtering) CA).
- ✅ Click on the certificate name and select “Delete” or “Erase».
The system will ask to confirm the action, you may need to enter PIN-The unlock code or fingerprint, once confirmed, will disappear from the list. If the list is empty or there is no "Delete" item, go to the next sections of the article.
☑️ Verification of certificate deletion
Removal through the developer menu
If the standard path doesn't work, you can use the developer's extended menu, which often helps when the security settings interface is bugged or obscures controls, and you need to start by activating the developer mode if you don't already have one.
Go to Settings. → On the phone and press quickly 7-10 once on the line “Version” MIUI» Or "OS version." You'll see a message that says, "You're a developer." Then go back to the main settings menu, go to the Additional. → For developers.
Inside the developer menu, scroll down to the "Network" or "Debugging" section, and we're interested in "Installation of Certificates" or "User Certificates."
| Parameter | Description of action | The result |
|---|---|---|
| Installation from the vault | Allows you to select a certificate file | Not used for removal |
| Clearing of credentials | Resets all user certificates | Complete removal of AdGuard |
| Checking applications | Scans APK for viruses | Security of the system |
Find the Clear credentials option, and clicking on this button will remove all user certificates, including AdGuard, which is a radical but effective method, and then reboot your phone.
What to do if the developer menu is hidden?
Specifics of removal on different versions of MIUI and HyperOS
Xiaomi’s shell is constantly changing, and menu layouts can vary. On older versions (MIUI 11, 12), the path often lay through Password & Security. In newer versions like MIUI 14 and the new HyperOS, Google changed security requirements, and certificate management could move.
In HyperOS and Android 13/14, certificates are often searched through a global search by settings. Click on the magnifying glass at the top of the Settings menu and type in a request for Certificate or Credential.
It is also worth considering the regional features of firmware:
- 🇪🇺 European version (Global) EEA): Strictly follow Google standards, the menu is located in the Privacy section.
- 🇷🇺 Russian version (RU): It may have additional encryption points associated with GOST, but the path to user certificates is standard.
- 🇨🇳 Chinese version (CN): The interface can be in Chinese, look for characters corresponding to "Security" and "Encryption».
If you’ve recently updated and can’t find old items, use a Settings Search – this is the most reliable way to navigate the confusing menus of modern smartphones.
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Use a Settings search. Type the word "certificate" or "credential" into the settings search bar, which is faster than manually searching all menus.
What to do if the delete button is inactive or hidden
Sometimes users are faced with a situation where the AdGuard certificate is visible in the list, but the delete button is either missing or not pressed (gray).This can occur if the application still has device administrator rights or runs in the background with increased privileges.
First, check for administrator rights. Go to Settings → Password & Security → Privacy → Special Access Rights → Administrator Apps. If you see AdGuard or a related component there, turn off the switch. Only then will the certificate become available for removal.
The second option is that the app hasn't been removed until the end. Go to Settings → Apps → All apps. Find AdGuard. If it's there, click "Delete." If the delete button is inactive, it may be a system application (which is rare for AdGuard, but it's possible when pre-installed).
⚠️ Note: Do not try to delete system files through root-righted file managers unless you are sure of your actions.This can lead to a cyclical bootloop of the Xiaomi phone.
If nothing works, try removing the certificate in Safe Mode. To do this, press the power button, then press the "Switch off" icon on the screen for a long time until the prompt to go to Safe Mode appears. In this mode, third-party applications do not start, and the deletion lock can be removed.
Cleaning DNS and resetting network settings
Even after the certificate is deleted, network settings can be saved that redirect traffic through AdGuard servers, which often happens if you used DNS Protection inside the application, and to ensure that you clear the tracks, you need to reset your network settings.
Go to Settings → Connection and Sharing → Reset Wi-Fi, mobile networks and Bluetooth. Click “Reset settings.” Importantly, after this action, you will have to re-enter passwords from all Wi-Fi networks and reintroduce Bluetooth devices. However, this ensures that no hidden proxy settings remain.
Also check the settings of the private DNS:
- Open Settings → Connection and Sharing → Private DNS.
- Make sure that you do not have a dns.adguard.com address.
- If the field is full, select the option “Auto” or “Disabled”.
These actions will completely clear the network stack of your Xiaomi from the ad blocker settings.
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Resetting your network settings is a radical but 100% effective way to remove any remnants of AdGuard settings, including DNS and proxy.
Possible problems and solutions
In rare cases, the certificate may "resurrect" after a reboot.This is a sign that there is another app left on the phone that reinstall-its AdGuard settings (such as some sort of cleaner or other blocker).
The problem may also be in the cache of Xiaomi’s Security service. Try to clear the data from the Security app itself. Go to Settings → Apps → All Apps → Security → Memory → Clear Data. This won’t delete your personal files, but will reset your antivirus and filter settings.
If you use a corporate profile or a phone number issued at work, the certificate could be installed through a MDM-In this case, you can not delete it without completely resetting to the factory settings (Wipe Data.