12 Reasons Why Mi Band 4 is Shutting Down From Xiaomi Phone – and How to Fix It

Why is your Mi Band 4 constantly breaking the connection to your Xiaomi phone?

Have you noticed that the Mi Band 4 fitness bracelet is constantly “lost” in the Mi Fit or Zepp Life app, and notifications come with a delay (or do not come at all)? The problem is not unique: according to service centers, up to 37% of Mi Band 4 owners face spontaneous disconnections from Xiaomi smartphones, the reasons are rooted in software bugs and hardware features of the devices.

In this article, we will look at all possible scenarios, from the banal discharge of the battery to firmware conflicts, and pay special attention to the pitfalls of the Xiaomi ecosystem: why the bracelet works consistently with the iPhone, but “gluts” with smartphones on MIUI. You will also find step-by-step instructions with illustrations (in the form of checklists) and answers to frequent questions in the FAQ.

Spoiler: 80% of the time, you can fix the problem without going to the service center. Start with Quick Solutions if you need to reconnect urgently.

⚡ Fast Solutions: 5 Steps to Getting to the Service

Before you dig deeper, do these basic steps. They help in 6 out of 10 cases:

Reboot your Xiaomi smartphone (hold Power + Volume up 10 seconds)

Turn off/turn on Bluetooth in the notification curtain

Remove the bracelet from the list of associated devices (Settings → Bluetooth)

Update Mi Fit or Zepp Life app on Google Play

Check the charge of the Mi Band 4 (at a level below 15%, the connection becomes unstable)

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If you've been doing this, and you've still turned off the bracelet, read on, and we'll look at the reasons for the complexity, from software to hardware.

Once a day.

Several times a week

Rarely, but accurately (1-2 times a month)

Never shuts down.

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🔍 Cause №1: Version Conflict MIUI and bracelet firmware

The most common problem is firmware incompatibility. Mi Band 4 was released from 2019 to 2021, and during this time Xiaomi has released dozens of updates for MIUI, while the firmware bracelet (file with the extension.fw) may be outdated or, conversely, too new for your version of MIUI.

How to check:

1. Open Mi Fit → Profile → Mi Band 4 → Update firmware.
2. Compare the current version with the latest one available. If you have an update, install it.
3. Check out the MIUI version: Settings → About Phone → MIUI version.

If the bracelet firmware update doesn’t help, try rolling back. MIUI For the stable version (for example, from 14th to 13th). MIUI».

📱 Cause №2: Bugs in Mi Fit or Zepp Life apps

Xiaomi has since rebranded some of the bracelets to the Zepp Life app, but Mi Fit still supports Mi Band 4.The problem is that both apps may conflict with each other or contain critical bugs.

Symptoms:

• 🔄 The bracelet is plugged in, but after 5-10 minutes it falls off.
• 📵 In Mi Fit, it says "Device disabled," even though Bluetooth is turned on.
• ⚠️ The application will crash when you try to synchronize the data.

Decisions:

1. Remove both apps (Mi Fit and Zepp Life) and install only one. For Mi Band 4, you’d better choose Mi Fit version 4.6.0 or later.
2. Clear the app cache: Settings → Applications → Mi Fit → Storage → Clear the cache.
3. Disable Battery Optimization for Mi Fit: Settings → Applications → Mi Fit → Battery → Without Limits

💡

If the bracelet is not available after reinstalling the Mi Fit, try connecting through the third-party Notify & Fitness for Mi Band app (available on Google Play), which often works more stable than the official one.

🔙 Cause №3: Problems with MIUI (how to roll back version)

Xiaomi is known for its firmware experiments, and sometimes MIUI updates break compatibility with accessories. For example, MIUI 14 has a bug that causes Bluetooth 4.2 devices (including Mi Band 4) to lose communication when the screen is locked.

If you suspect that the firmware of the phone is to blame, try to roll back to the stable version.

💡

The MIUI rollback is a last resort. Before you do that, try resetting the network settings on your phone (Settings → SIM- Cards and Mobile Networks → Network Reset).

🔋 Cause №4: Battery discharge or battery failure

The Mi Band 4 is equipped with a 135 mAh battery, and over time, its capacity decreases, and at a charge level below 20%, the bracelet begins to save energy by turning off the Bluetooth module.

• 🔌 Charging contacts are oxidized (the bracelet shows 100% but discharges quickly).
• 🔥 Battery bloating (see by body deformation).
• ⚡ The power controller is out of order (the bracelet does not charge or shuts down at 50% charge).

How to diagnose:

1. Check the actual charge level: plug the bracelet into the charge and see how fast the percentage goes, and if it goes from 0 to 100% in 10 minutes, the battery is broken.
2. Check the charging contacts on the bracelet and cable: they should be clean, without green plaque.
3. Try charging the bracelet from another source (e.g. power bank) if it doesn't respond, the power controller is a problem.

💡

To clean the contacts, use a cotton swab dipped in isopropyl alcohol (not in water!).

If the battery is swollen or the bracelet does not hold a charge for more than 6 hours, a replacement is required. The cost of repairs at Xiaomi service centers is about 1,200-1,500 ₽ (for 2026).

📶 Cause №5: Bluetooth interference and conflicts with other devices

The Bluetooth module in the Mi Band 4 operates at 2.4 GHz, which is congested in urban areas.

• 📡 Wi-Fi routers (especially on channels 1-6)
• 🎧 Wireless headphones or speakers.
• 🖥️ Devices with Bluetooth 5.0+ (they clog up old protocols).
• 🚗 Automotive Hands-Free Systems.

How to reduce interference:

1. In router settings (192.168.0.1 or 192.168.1.1), change the Wi-Fi channel to 11-14.
2. Disable other Bluetooth devices connected to your phone.
3. Enable High Accuracy mode in the location settings (Settings → Security & Location → Mode → High Accuracy).
4. If you are in a car, try to disable the Bluetooth connection to the tape recorder.

If the problem only manifests itself in certain places (for example, at work or in the subway), external interference is most likely to be to blame, in which case only changing the firmware of the bracelet to a more noise-resistant one will help (see the section "Castom firmware").

🛠️ Reason №6: Unofficial firmware and “curved” updates

Many users install custom firmware on the Mi Band 4 (such as the Amazfit Mod or Mi Band 4 Custom Firmware) to unlock new features, but such firmware often contains bugs that cause the bracelet to:

• 🔄 Infinitely reconnects to the phone.
• 📵 Not displayed in the list of Bluetooth devices.
• ⚠️ It gives an error called "Data failed to sync."

How to return the original firmware:

1. Download the official firmware from the Amazfit WatchFaces website (choose the version for your Mi Band 4 model – XMSH07HM or XMSH08HM).
2. Install Mi Band 4 Tools (available on 4PDA)
3. Connect the bracelet to your PC via Bluetooth and flash the original.fw file.

💡

If the bracelet is warranty-free, try resetting it to factory settings first (In Mi Fit: Profile → Mi Band 4 → Untie the device).

🚨 Cause №7: Hardware malfunctions (when it's time for service)

If none of the above methods worked, perhaps the problem is the "hardware" of the typical Mi Band 4 hardware malfunctions:

If you suspect a hardware malfunction, do not try to disassemble the bracelet yourself - the body of the Mi Band 4 is hermetically glued, and if you do not open it carefully, you can damage the display or plumes.

💡

Before visiting the service, make a backup copy of the bracelet data via Mi Fit (Profile → Mi Band 4 → Backup).

❓ FAQ: Frequent questions about Mi Band 4 issues