Why Mi Band 4 is constantly disconnected from the smartphone Xiaomi Redmi – a full analysis of the problem

The problem of spontaneously disconnecting the Mi Band 4 from Xiaomi Redmi smartphones is one of the most common complaints users have: the wristband can lose communication both minutes after connecting and after prolonged operation, making it impossible to synchronize data about steps, sleep or notifications, the reasons are rooted in both hardware features of the devices and software conflicts between the firmware Mi Band and MIUI.

Many people mistakenly blame the problem on the bracelet or phone, but 80% of the time it is the settings, background processes or outdated versions of the software. For example, after the update of MIUI 12.5 on Redmi Note 9, users massively encountered a bug in which the Mi Band 4 shut down after 5-10 minutes due to aggressive optimization of power consumption. In this article, we will analyze all possible causes, from banal to hidden, and give clear instructions for troubleshooting.

If your bracelet only turns off in certain conditions (such as when locking your phone screen or while making calls), it narrows the search for a problem. Key point: Mi Band 4 uses Bluetooth 4.2 LE protocol, which is sensitive to interference from other wireless devices, background tasks, and even physical obstacles (for example, if the phone is in the bag and the bracelet is on the hand).

1. Conflict of firmware versions: bracelet vs smartphone

The most common cause of outages is software version incompatibility. For example, if the Mi Band 4 has 1.0.9.58 firmware installed and the Redmi has MIUI 13 installed, there may be failures due to changes in the data exchange protocol. Xiaomi regularly updates the energy saving algorithms in MIUI, which sometimes leads to the forced break of Bluetooth connections with “non-priority” devices.

Check the firmware version of the bracelet in the Mi Fit application:

1. Open Mi Fit → go to the profile of the bracelet.
2. Slap the icon "⚙️" (setting) → The bracelet.
3. Compare the current version with the current one on Xiaomi.

Critical version combinations that cause shutdowns:

• 📱 MIUI 12.5 + bracelet on firmware older than 1.0.9.36 → Bluetooth background scanning bug.
• 📱 MIUI 13/14 + bracelet 1.0.7.xx → protocol GATT.
• 📱 Redmi with Android 11+ + Mi Fit (version below 4.6.0).

Decision:

1. Update the firmware of the bracelet through Mi Fit (section About the bracelet → Software update).
2. If the update is not available, force the bracelet through the Mi Band 4 Tools (instruction below).
3. A rollback to a stable version of MIUI (e.g., from MIUI 14 to MIUI 13.0.5) can help if a bug appears after an upgrade.

2. Aggressive battery optimization in MIUI

Xiaomi Redmi is known for its tight energy-saving policies, which often strangle background processes, including a Bluetooth connection to the bracelet. For example, after 10 minutes of inactivity, the system can force the connection to the Mi Band 4 to save charge.

How to check if optimization is to blame:

1. Go to Settings → Applications → Application Management.
2. Find Mi Fit → Battery Limits.
3. If you have a status of “limited” or “optimized” – that is the reason.

Ways to disable optimization:

• 🔋 In the Mi Fit settings, select Without Limitations.
• 🔋 Add Mi Fit to Autostart (Settings section) → Annexes → Auto-start).
• 🔋 Enable Background Activity for Mi Fit and Bluetooth Share.

Disable optimization for Mi Fit| Add Mi Fit to autorun | Allow background Bluetooth | Turn off Charge Saving mode-->

Important: Some Redmi models (such as the Note 10 Pro) have a hidden restriction on background Bluetooth usage after upgrading to MIUI 13.

Settings → Special features → Developer settings → Disable “Limit background processes”

3. Problems with the phone's Bluetooth module

Mi Band 4 works on Bluetooth Low Energy (BLE) protocol, which is sensitive to interference. If your Redmi has other devices connected at the same time (earphones, speakers, second bracelet), there can be a conflict of channels, leading to a communication breakdown.

How to diagnose the problem:

• 🎧 Disable all other Bluetooth devices and check the stability of the connection.
• 📶 Go to Settings. → Connections → Bluetooth and see if the connection icon flashes (this is a sign of frequent reconnection).
• 📱 Install the nRF Connect (Android) app and check signal stability BLE bracelet.

Decisions:

1. Reset Bluetooth settings on your phone: Settings → System → Reset settings → Network reset
2. If the problem persists, reflash the Bluetooth module via Fastboot (instructions for advanced users below).
3. On some Redmis (such as Note 8 Pro) it helps to disable the dual Bluetooth connection function in the developer settings.

Critical information: Redmi with MediaTek chipset (e.g. Redmi) 9A) post-refresh MIUI 13 can be dropped MAC-The Bluetooth address, which leads to the bracelet being forgotten, will only help to completely reset the phone to factory settings.

4. Mi Fit Bugs and Alternatives

The official Mi Fit app is often a source of problems due to:

• 🐞 Unstable updates (for example, version 4.7.0 massively "reset" the connection with the bracelets).
• 📥 Cache conflicts (synchronization errors accumulate).
• 🔒 Restrictions of regional versions (for example, Chinese bracelet firmware is not compatible with global Mi Fit).

How to fix:

1. Clear cache and Mi Fit data: Settings → Applications → Mi Fit → Storage → Clear cache + Clear data
2. Install the old version of Mi Fit (e.g. 4.6.0) if the problem has occurred after the update.
3. Try alternative applications: 🔹 Notify & Fitness for Mi Band (more features, but can lay down). 🔹 Mi Band Master (supports unofficial firmware).

If the bracelet is turned off when the data is synchronized, try:

1. Disable "Autosync" in the Mi Fit settings and start it manually.
2. Turn on "Airplane Mode" on your phone for 10 seconds, then reconnect to the bracelet.

How to check:

1. Hold the bracelet as close to the phone as possible (10 cm) If the connection is stable, the problem is interference.
2. Try connecting the bracelet to another phone (not Xiaomi), and if the shutdowns continue, it's the bracelet.
3. Check the battery status of the bracelet through the Mi Band 4 Tools app (Battery Info section).

Decisions:

• 🔌 If the bracelet discharges in a few hours, replace the battery (cost) ~500-800 rubles.).
• 📡 Switch Wi-Fi router to 5 GHz (if it supports).
• 🛠️ If your phone falls, check the Bluetooth module at the service center (repair price) ~1500–30 rubles.).

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If the bracelet only turns off in certain places (such as at work or at home), the problem is almost certainly in external interference, not in devices.

6 Conflict with other Xiaomi services

Xiaomi integrates its devices into a single ecosystem, but sometimes it plays a cruel joke, for example, if the phone is turned on:

• 🔄 Mi Cloud Sync (Sync with Xiaomi Cloud).
• 🏠 Mi Home (Management of a Smart Home).
• 📍 Smart lock (unlocking the phone on the bracelet).

These services can compete for Bluetooth connectivity, causing Mi Band 4 shutdowns.

How to fix it:

1. Disable Smart Lock: Settings → Screen Lock → Smart Lock → Disable Mi Band
2. In Mi Home, turn off automatic connection to devices (Section Profile → Automation).
3. If you use Xiaomi Wear (an alternative to Mi Fit), remove it – it conflicts with the official app.

Hidden bug: Some Redmis with MIUI 13+ run a background process called com.xiaomi.bluetooth that forcibly breaks connections to "non-priority" devices to disable it:

1. Install ADB- Drivers on the PC.


2. Connect the phone and do:




adb shell pm disable-user --user 0 com.xiaomi.bluetooth




3. Reboot the phone.

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After the shutdown, com.xiaomi.bluetooth may stop working some functions of the smart home, but the connection with the bracelet stabilizes.

7. Resetting and flashing of the bracelet

If nothing works, you're left with a full reset of the Mi Band 4 or a flashing, which is a last resort, but it solves the problem 90 percent of the time.

Resetting instructions:

1. On the bracelet, go to Settings → About the bracelet → Reset (or press the button for 15 seconds).
2. In Mi Fit, remove the bracelet from the list of devices.
3. Reboot the phone.
4. Re-attach the bracelet through Mi Fit.

If the reset does not help, try the bracelet through Mi Band 4 Tools:

• 🔧 Download Gadgetbridge (alternative firmware).
• 🔧 Connect the bracelet to your PC via Bluetooth and follow the instructions in the program.
• 🔧 After the firmware, reset again.

Important: Flashing through informal tools is warranty-free and can lead to a bracelet brick.

FAQ: Frequent questions about Mi Band 4 shutdowns

If none of these methods worked, it may be a hardware malfunction of the bracelet or phone, in which case we recommend contacting the Xiaomi service center or considering buying a new device (for example, Mi Band 6 or 7, where such bugs are less common).

Before visiting the service, save the error log from the Mi Fit application (section Reviews → Error log) - this will help specialists diagnose the problem faster.

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In 60 percent of cases, the problem is solved by cleaning the Mi Fit cache and turning off battery optimization, and only 5 percent of the malfunctions require repair or replacement of the device.

⚠️ Warning: If after all the manipulations, the bracelet still shuts down after 1-2 minutes, check it on another phone.If the problem recurs, it is a 100% malfunction of the Mi Band 4 (most often the Bluetooth module of the bracelet fails).