When the fingerprint scanner on your Xiaomi 15 Ultra stops recognizing your finger, unlocking the phone becomes slow and frustrating. This issue often shows up suddenly, even when the sensor worked fine before. In most cases, the problem is caused by software settings, sensor interference, or how the fingerprint was registered, and all of these can be fixed with a few targeted steps in 2025.
Why Your Xiaomi 15 Ultra Fingerprint Scanner Is Not Recognizing
- The registered fingerprint data is incomplete or outdated.
- The screen protector is interfering with the fingerprint sensor.
- Fingerprint sensor calibration is slightly off after a software update.
- The finger or sensor surface is dirty or slightly wet.
- Power or performance restrictions are limiting biometric response.
1. Clean the Fingerprint Sensor Area
The under-display fingerprint scanner relies on clear contact between your finger and the screen. Even light moisture, oil, or dust can prevent proper recognition.
Wipe the lower portion of the screen with a clean microfiber cloth, and then make sure your finger is completely dry.
Lock the phone, and then try unlocking it again using your registered fingerprint.
2. Re-Register Your Fingerprint
If your fingerprint was saved when your finger was dry, injured, or positioned poorly, recognition accuracy drops over time. Re-registering creates a fresh and more accurate scan.
Open Settings, and then tap Passwords and security.
Tap Fingerprint unlock, and then delete the existing fingerprint before adding a new one.
3. Add the Same Finger Twice
Adding the same finger more than once improves recognition accuracy. This helps the sensor read your finger from different angles and pressure points.
Open Settings, and then tap Passwords and security.
Tap Fingerprint unlock, and then register the same finger again using a slightly different angle.
4. Check Screen Protector Compatibility
Not all screen protectors are designed for ultrasonic or optical fingerprint sensors. Thick or low-quality protectors often block the sensor signal.
Remove the screen protector temporarily, and then test fingerprint unlocking.
If it works normally, replace the protector with one labeled as fingerprint compatible.
5. Enable Fingerprint Sensitivity Options
Some display and security settings reduce fingerprint responsiveness to save power. Adjusting these options can restore normal performance.
Open Settings, and then tap Passwords and security.
Tap Fingerprint unlock, and then enable any sensitivity or enhanced recognition options available.
6. Restart the Phone
A restart refreshes biometric services and clears temporary system conflicts. This is especially useful after updates or long uptime.
Swipe down from the top of the screen to open Quick Settings, and then tap the Power icon.
Tap Restart, and then wait for the device to boot fully before testing the scanner again.
7. Update System Software
Fingerprint recognition issues are sometimes caused by software bugs. Xiaomi regularly releases fixes through system updates on HyperOS.
Open Settings, and then tap About phone.
Tap System update, and then install any available updates.
Once the fingerprint scanner is working again, unlocking your Xiaomi 15 Ultra should feel instant and reliable. Most recognition issues are not hardware failures, and they usually disappear once the sensor is cleaned, recalibrated, or updated.
FAQs
Why does my fingerprint scanner fail only at night or indoors?
Dry skin and low ambient light can affect optical fingerprint sensors. Slightly moistening your finger or increasing screen brightness often helps.
Does fast charging or overheating affect fingerprint recognition?
Yes. When the phone heats up, sensor accuracy may temporarily drop. Let the device cool down before testing again.
Should I reset my phone if the fingerprint scanner still fails?
A full reset is rarely necessary. If all steps fail, contact Xiaomi support to check whether the sensor hardware needs inspection.
