| Blue trails sometimes appear when I use my HUAWEI phone/tablet |
Problem:
Blue trails occasionally appear when the user slides on the phone/tablet screen, as shown in the following figure.
Cause:
After you enable the knuckle gesture control or the Multi-Window feature, a blue trail will appear when you slide on the screen with your knuckle.
Solution:
The blue trail does not affect your actual usage. If you wish to clear the blue trail, perform the following steps:
- Go to Settings > Smart assistance (Accessibility) > Motion control (Shortcuts & gestures), and turn off the knuckle gesture controls, including Smart screenshot, Draw, Split screen, Screenshot, and Record screen.
Steps 2 and 3 apply only to the following phone models running EMUI 10.1 or later, or Magic UI 3.1 or later:
HUAWEI Mate 20, HUAWEI Mate 20 Pro, PORSCHE DESIGN HUAWEI Mate 20 RS, HUAWEI Mate 20 X (4G), HUAWEI Mate 20 X (5G), HUAWEI P30, HUAWEI P30 Pro, HONOR 20, HONOR 20 Pro, HONOR V20, HONOR Magic 2, HUAWEI nova 5 Pro, HUAWEI Mate X, HUAWEI Mate Xs, HONOR 30 Pro, HONOR 30 Pro+, HONOR 30, HONOR 30S, HUAWEI nova 6, HUAWEI nova 6 5G, HUAWEI nova 7 5G, HUAWEI nova 7 Pro 5G, HUAWEI nova 7 SE, HONOR V30, HONOR V30 PRO, HONOR Play4 Pro, HUAWEI Mate 30 Series, HUAWEI P40 Series, HONOR X10, HONOR 20S, HUAWEI Mate 40 Series, HUAWEI Mate X2
- If the issue persists, go to Settings > Smart assistance (Accessibility) and enable Multi-Window. Use your knuckle to draw a horizontal line on the screen. In the displayed Multi-Window dialog box, select Don't remind me again.
3. If no Multi-Window dialog box displays after you perform step 2, go to Settings > System updates > Reset > Restore all settings, and then repeat step 1 and step 2. This issue will be resolved in a later version. Please stay tuned for system updates and update your device at your earliest convenience.
The following settings will be restored: Wi-Fi, mobile data, and Bluetooth network settings, home screen layout, fingerprint data, facial information, lock screen password, and permission settings for all apps (system apps and third-party apps). For versions earlier than EMUI 5.0, App Twin will be disabled, and the twin app data will be erased.