Why Xiaomi Redmi Note 9S is not updated – all the reasons and ways to solve it

Xiaomi Redmi Note 9S is one of the most popular smartphones of 2020, but many users are faced with a problem: the device stops receiving MIUI updates or gets stuck on the old version of the firmware. What is the reason? This can be due to errors in Xiaomi servers, locking the bootloader, damage to system files or even artificial restriction on the part of the manufacturer.

In this article, we’ll look at 10 of the main reasons why your Redmi Note 9S (codename curtana) isn’t updated, and give you step-by-step instructions to fix each of them, from simple solutions like resetting to manual firmware via Fastboot, you’ll find the answer regardless of your technical background.

Particular attention will be paid to the hidden restrictions of Xiaomi on updates for older models that the company does not advertise, but which can block updates even with a proper Internet connection and sufficient disk space.

1. Xiaomi server problems: why the update is not downloading

Most often, the Redmi Note 9S is not updated due to malfunctions on Xiaomi servers.The company periodically suspends the distribution of firmware for certain regions or models - this may be due to:

• 🔄 Staged rollout – Update is first received 10-20% Users are waiting for the rest 1-2 weekdays.
• 🚧 Technical Works – Servers may not be available due to upgrades or DDoS attacks.
• 🌍 Regional restrictions – some firmware is blocked for specific countries (for example, for Russia due to sanctions).

How do you check if the servers are to blame? Try downloading the firmware manually through the official MIUI Downloads website. If the page doesn't open or the files don't download, the problem is on Xiaomi's side.

⚠️ Please note: if your Redmi Note 9S purchased in China (domestic version), it may not receive global updates, in which case you will need to unlock the bootloader and firmware international version. MIUI.

2. Insufficient disk space or corrupted cache files

MIUI It requires a minimum of 1.5-2 GB of free download space and install the update. 9S Less than 10% of the free space, the system automatically blocks updates. → Warehouse.

Another common cause is corrupted update cache files, which are in the /cache folder and can interfere with downloading new versions.

1. Go to Settings → Applications → Application Management.
2. Find System Update (or com.android.updater).
3. Press Warehouse. → Clear the cache.
4. Reboot the phone.

Clear the cache of the application "System Update"|Free up at least 2 GB of space|Connect to a stable Wi-Fi|Charge your phone to 50% or higher|Shut down. VPN (if used)-->

If the update does not download after cleaning the cache, try to remove the folder with downloads manually through the file manager:

Internal memory → MIUI → download → Rom

Delete all files with the.zip extension in this folder.

3. Bootloader lock and unlock status

Xiaomi is blocking the bootloader on all its devices, including the Redmi Note 9S. If you've ever tried to unlock it through the Mi Unlock Tool but haven't completed the process, it could result in a ban on updates.The company is restricting updates for devices with unofficial bootloader status.

Check the status of the loader can be as follows:

1. Turn off the phone.
2. Press the Power button + Volume down to enter the Fastboot.
3. Connect the device to the PC and type the command: fastboot oem device-info
4. If the answer is Device unlocked: false, the bootloader is locked. If true, unlocked.

⚠️ Note: If you have unlocked the bootloader but have not installed a custom recavére (for example, TWRP), Trying to upgrade through the standard Recovery menu can cause the device to break down.

4. Errors in the build.prop file or modified firmware

If you have previously modified system files (e.g., through Magisk, Xposed, or manually edited build.prop), it could break the update mechanism. Xiaomi checks the integrity of the system before installing OTA, and if it finds inconsistencies, blocks the process.

Frequent signs of modified firmware:

• 🔧 Modified Assembly Number in Settings → The phone.
• 📱 Root rights (applications like Magisk Manager).
• 🖼️ Custom icons or themes that are not removed through standard settings.

Decisions:

1. Restore the standard build.prop via ADB: adb pull /system/build.prop adb push build.prop /system/ (root rights required).
2. Remove the root via Magisk (Uninstall → Complete Uninstall option).
3. Swipe the stock firmware through Fastboot (instructions in the next section).

5 Manual updates via Recovery or Fastboot

If the automatic update doesn't work, you can install the firmware manually. There are two methods available for the Redmi Note 9S (curtana):

Method 1: Recovery (without data loss)

1. Download the latest stable firmware for your model from the official website (select Recovery ROM).
2. Rename the file to update.zip and place it in the root of internal memory.
3. Go to Settings → About Phone → System Update → Three Dots (menu) → Select a firmware file.
4. Select update.zip and confirm the installation.

Method 2: Through Fastboot (complete flashing)

This method is suitable if Recovery does not work or the device is blocked. You will need a PC with Mi Flash Tool drivers installed.

1. Download Fastboot ROM for Redmi Note 9S (curtana) with Xiaomi Firmware Updater.
2. Unpack the archive in a folder without Cyrillic characters.
3. Launch the Mi Flash Tool, connect your phone in Fastboot mode.
4. Select the firmware folder and click Refresh → Flash.
5. Once completed, the phone will automatically restart.

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Before you run through Fastboot, be sure to check the firmware version! Installing an older version on top of a newer one can result in data loss or an anti-rollback error.

6. Xiaomi restrictions on older devices: a hidden update policy

Xiaomi does not advertise, but practices artificially limiting updates for devices older than 2-3 years. Redmi Note 9S was released in 2020, and since 2023, many users note that:

• ⏳ Updates come less frequently (once every 3-6 months instead of monthly).
• 🔄 New versions MIUI contain fewer changes (only security fixes).
• 🚫 Some regions are completely deficient (for example, European firmware for Redmi Note). 9S They stopped updating after MIUI 14).

Check whether your Redmi Note 9S is in the list of “obsolete” devices, you can on the forums XDA-Developers or in Telegram channels dedicated to MIUI.

If your device is no longer officially supported, there are two options left:

1. Switch to custom firmware (like LineageOS or Pixel Experience).
2. Swipe the latest available version of MIUI manually (see Section 5).

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Xiaomi doesn’t have to keep the device up forever. After 3-4 years, updates can stop even for properly functioning smartphones, which is standard practice for most manufacturers except Google (Pixel) and Apple (iPhone).

7.Mi Account issues and region-based linking

If you have a Redmi Note 9S It was bought in one region and used in another (for example, brought from China to Russia), this can block updates. Xiaomi links firmware to the region of the Mi Account, and if they do not match up, it is possible to block the updates, OTA-updates don't come.

How to check and correct:

1. Open Settings → Mi Account → Region.
2. If the region is not the same as the firmware (for example, the phone is on global firmware, and the account is tied to China), follow the following steps: Sign out of the Mi Account. Reset network settings (Settings) → SIM-maps and networks → Reset network settings. Go back to the right region.

If the problem persists, try changing the firmware region through Fastboot (see Section 5). To do this, download the firmware for the desired region (for example, Global instead of China) and run it.

⚠️ Warning: Changing the firmware region can cause all data to be reset! pre-backup via Settings → Additionally. → Backup and reset.

8 Hardware problems: memory, battery, connectors

Less often, the reason for the lack of updates are physical malfunctions, but they should also be excluded:

• 🔋 Worn-out battery (less than 30% health) – the phone may shut down during the upgrade, interrupting the process.
• 💾 Damaged flash memory – if memory “drops”, firmware files can be downloaded with errors.
• 🔌 Faulty connector USB/Type-C — interferes with the connection to the PC for manual firmware.

Check the battery health through the engineering menu:

#4636### → Information about the battery

If the value of health is different from Good, it is time to replace the battery.

Use the AIDA64 app (Storeroom → Memory Test) to diagnose memory. If the test shows read/write errors, contact the service center.

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If the phone turns off when you try to upgrade or shows an error "failed to mount /system", this is a sign of hardware malfunction, in which case the self-firmware can aggravate the problem - it is better to take the device for repair.

Frequently Asked Questions (FAQ)