Lock screen while calling Xiaomi Redmi 9: 3 ways to protect against accidental touches

Accidental tapping of the screen during a phone conversation is a common problem for owners of Xiaomi Redmi 9. One careless touch with the cheek or ear can lead to a microphone shutdown, speakerphone activation or even a call reset, especially for smartphones with large displays, where the touchpad occupies almost the entire front surface.

In this article, we’ll look at all the ways you can lock your screen while you’re on a call, from standard MIUI settings to hidden features and third-party apps, how to get rid of random taps forever without resorting to drastic measures like turning off your sensor completely, and why locking sometimes doesn’t work and how to fix it.

Why is the screen not automatically locked when you call?

By default, the Xiaomi Redmi 9 should lock the screen when it is raised to the ear thanks to the built-in proximity sensor. However, many users are faced with the fact that the feature does not work correctly or does not work at all.

• 🔹 Pollution of the proximity sensor – dust, greasy prints or protective film interfere with the correct operation of the sensor.
• 🔹 Sensor damage after screen fall or repair.
• 🔹 Failure to work MIUI — especially after the firmware update.
• 🔹 Disabled function in settings – sometimes users accidentally deactivate the lock.
• 🔹 Conflict with third-party applications, such as launchers or gesture control programs.

Before you set the lock manually, check the proximity sensor.

1. Open the Phone app and dial ##6484## (test code to check sensors).
2. Put your hand up to the top of the screen (where the sensor is located), and if the screen goes out, the sensor works.
3. If there is no reaction, clean the sensor with a soft cloth or contact the service.

Method 1: Enabling locking through MIUI settings

The easiest way is to activate the built-in lock-in feature during a call, which is called Lock-on-Approach in MIUI, and is usually enabled by default. If not, do the following:

1. Go to Settings → System and device → Additional settings.
2. Select the Special Opportunities item.
3. Scroll down and find the screen lock section when approaching.
4. Activate the switch if it is switched off.

After that, the screen should go out when you hold the smartphone to your ear. If the function was already on, but did not work, try resetting the sensor settings:

• 📱 Go to Settings. → The phone.
• 🔧 Press 5 times on the version MIUI, activate the developer mode.
• 🔄 Return to the additional settings → For developers.
• 🔍 Find the item Reset sensors and confirm the action.

Clean the sensor of dirt and film |

Check the reaction with the test code ##6484##|

Enable lock in "Special Opportunities" |

Reset sensor settings in developer mode-->

Method 2: Use the "Double touch to lock" gesture

If the proximity sensor is unstable, you can lock the screen manually with a double-touch gesture, which allows you to lock the display with one motion without interrupting the conversation.

To activate it:

1. Open Settings → Screen lock and password.
2. Select Additional Locking Settings.
3. Activate the option of Double-Tap to lock.

Now, when you call, you just need to touch the screen twice (not by icons!) to turn it off, which is convenient if you talk on the phone often in noisy places and you need to quickly lock the sensor so you don't accidentally tap the speaker.

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If double tap doesn’t work, check if it conflicts with other apps’ gestures (like Nova Launcher or Fluid Navigation).

Method 3: Applications for Forced Screen Locking

If standard methods don't work, you can install a third-party app, such as Proximity Sensor Reset or Screen Off and Lock, which allows you to force the screen to lock during a call.

Let’s look at the Screen Off and Lock:

1. Download the app from Google Play.
2. Open it and grant permission to use over other windows.
3. In the application settings, find the Automatic Lock item when calling.
4. Activate the function and select a delay (e.g., 2 seconds after the conversation starts).

The advantage of this method is that locking works even if the proximity sensor is faulty, but note that some applications may conflict with MIUI and cause freezes.

Table: Comparison of screen locking techniques during a call

Important: If none of these methods work, the problem may be a hardware malfunction of the proximity sensor, in which case, contact the service center for diagnosis or replacement of the sensor.

What to do if the lock is not working?

If you have enabled all settings but the screen is still not locked during the call, try the following steps:

1. Restart your phone – sometimes a banal reboot helps, especially after a MIUI update.
2. Reset the Phone app settings: Go to Settings → Apps → Application Management. Find the phone, open the Storage and click Reset settings.

Update the firmware

MIUI

Check conflicts with other applications

Fluid Navigation Gestures

Edge Gestures

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If the lock stopped working after the MIUI update, try rolling back on the previous firmware version or wait for a patch from Xiaomi.

⚠️ Attention: Some users try to solve the problem by unplugging the protective film in the proximity sensor area. This may help, but you risk damaging the oleophobic coating of the screen.

Additional settings for comfortable calls

Besides locking the screen, the Xiaomi Redmi 9 has other useful features to improve the quality of calls:

• 🎧 Voice amplification - in the call settings (Settings) → Sound. → Voice amplification can increase the volume of the interlocutor.
• 🔇 Noise suppression – activated in the same settings, reduces background noise.
• 📞 Quick response – allows you to send SMS-Messages directly during incoming call (included in Settings) → Calls. → Quick answer).
• 🔄 Screen Autoturn – Turn it off during a conversation to avoid accidental image flipping.

We also recommend setting the vibration when calling, which will help you not miss the incoming call if the phone is in your pocket.

1. Go to Settings → Sound → Vibration when calling.
2. Choose the right rhythm of vibration or create your own.

FAQ: Frequent questions about locking the screen during a call

⚠️ Note: If you use custom firmware (like LineageOS or Pixel Experience), standard settings MIUI In this case, the locking of the screen will have to be configured via Magisk or Xposed modules.