Why Xiaomi Redmi 9C itself change wallpaper on the lock screen and desktop?

Introduction: Why the smartphone itself changes the background images

You can install beautiful wallpaper on your Xiaomi Redmi 9C, But after a few hours (or even minutes), they suddenly reset to a standard background? This is a common problem faced by owners of budget Xiaomi smartphones. MIUI — manufacturer's shell.

In this article, we’ll look at 7 main reasons why wallpaper changes on its own, from automatic themes updates to malicious apps, and you’ll find step-by-step instructions on how to regain control of the screen, and tips to prevent re-failures. If a problem arises after updating your firmware or installing new apps, the solutions will be different — so read each section carefully.

Important: Some methods require changes in system settings. If you are not sure about your actions, first back up your data through Settings → About Phone → Backup will save you from losing important information when resetting.

1. Automatic update of topics in MIUI

The most common reason for spontaneous wallpaper changes on Redmi 9C is the work of the built-in Themes service. By default, MIUI can automatically download and apply new themes, including background images, if the appropriate option is enabled. This is part of the Xiaomi ecosystem that syncs with the Mi Account.

How to check and disable auto-update:

1. Open the Themes app (the icon with a brush on your desktop).
2. Go to Profile → Settings → Auto-Update Themes.
3. Turn off the slider Automatically apply new themes.
4. Also check the My Downloads section – there are probably several options for wallpaper that the system applies cyclically.

If you don't have an auto-update, update the Themes app via Google Play, which may not be available in older versions. Once you disable this feature, the wallpaper will stop changing, but you can manually install new themes from the directory.

Failures in the launcher MIUI

The launcher (the program responsible for displaying the desktop) on the Redmi 9C can crash due to a lack of RAM or conflicts with other applications. If the wallpaper is reset to standard after rebooting or locking the screen, the problem is most likely in the launcher.

How to fix it:

• 🔄 Restart Launcher: Go to Settings → Annexes → Application management, find Louncher MIUI, Click Stop and Clear the Cache.
• 📱 Reset the launcher settings: in the same application settings, select Storage → Reset settings (does not delete data, only returns standard settings).
• 🔧 Update Launcher: Check for updates in Google Play (search on request "MIUI Launcher").

If the problem persists, try installing a third-party launcher (like Nova Launcher or Lawnchair) to help determine if the crash is related to Xiaomi’s system launcher. Note that when using an alternative launcher, some MIUI features (such as gestures or widgets) may not work properly.

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Before changing the launcher, export the current location of the icons through the launcher settings – this will make it easier to restore the desktop.

3. Conflict with wallpaper applications

Wallpaper programs you install (such as Zedge, WallpapersCraft, or Google Wallpaper) may conflict with MIUI system settings. Some of them have the function of automatically changing backgrounds on a schedule or when changing the time of day.

What to do:

1. Check the settings of each wallpaper app – turn off options like Automan, Dynamic Wallpaper or Sync with the Weather.
2. Remove unnecessary wallpaper apps through Settings → Apps.
3. If you use Google Wallpaper, turn off the Daily Wallpaper feature in the app settings.

Once you delete the conflicting apps, restart your phone, and if the wallpaper keeps changing, the problem goes deeper, perhaps in system files or firmware.

4. Viruses and malware

Rarely, but possible: Your Redmi 9C may have malware installed that changes wallpaper to display ads or collect data, often masquerading as useful utilities (optimizers, cache cleaners) or pirated applications.

Signs of infection:

• 🚨 Wallpaper changes to banner ads or strange images.
• 📴 Pop-up windows appear with a suggestion to install other applications.
• 🔋 The phone is quickly discharged or warmed for no reason.

How to check and clean your phone:

1. Install an antivirus (such as Malwarebytes or Dr.Web Light) and perform a full scan.
2. Check the list of installed apps in Settings → Apps – remove suspicious programs.
3. Disable installation from unknown sources: Settings → Privacy → Special permissions → Install unknown applications.

⚠️ Warning: If the antivirus detects threats but cannot remove them, reset to factory settings via Settings → Additionally. → Recovery and reset. Pre-save important data!

5. Failures after MIUI update

Firmware updates sometimes lead to bugs, one of which may be wallpaper reset. If the problem occurs immediately after the MIUI update, try the following steps:

Solutions:

If none of the methods worked, the new version of MIUI may have a bug that developers don’t know about yet, in which case you either have to wait for a patch or roll back to the previous version of the firmware (this requires unlocking the bootloader and can cancel the warranty).

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After each major MIUI update, check the key functions (wallpaper, notifications, gestures) – this will help to identify bugs in time.

6. synchronization errors with Mi Account

If you use a Mi Account and theme sync is enabled, the wallpaper may be reset when you update data on Xiaomi servers.

• 🔄 You logged into an account on another device and changed the subject.
• 📱 On the servers Xiaomi has failed synchronization.
• 🔧 In the account settings enabled automatic application of themes.

How to turn off the synchronization of wallpaper:

1. Open Settings → Accounts → Mi Account → Synchronization.
2. Find the Topic item and turn off the slider.
3. Also check the Settings section → Themes → Profile → Synchronization settings.

If you don't want to turn off the sync completely, try manually applying the wallpaper through the gallery and then block them from changing.

1. Set the wallpaper through the Gallery → Set up how → Wallpaper.
2. In the theme settings (Themes → My Wallpaper), click on three dots next to the selected background and select Secure (if the option is available).

7 Hardware problems (rarely but possible)

In extremely rare cases, spontaneous wallpaper changes can be linked to a phone memory malfunction.If the Redmi 9C fell, overheated or was exposed to moisture, it could damage the memory sectors where the system settings are stored.

Signs of hardware problems:

• 💥 The phone accidentally reboots.
• 📉 Applications often fly out with an error.
• 🔋 The battery discharges unevenly (for example, from 50% to 1% in a few minutes).
• 📱 Wallpaper is reset along with other settings (language, date, brightness).

What to do:

1. Check your memory health through the Engineering Menu: Enter the Phone code ##4636## and select Testing.
2. If the phone is warranty, contact the Xiaomi service center.
3. If the warranty is over, try flashing the phone over Fastboot (requires skills).

⚠️ Please note: Do not try to disassemble Redmi by yourself. 9C It's a memory test, and it can cause the plumes or the display to break, and it's better to trust the hardware diagnostics to the specialists.

FAQ: Frequent questions about changing wallpaper to Xiaomi