There are colored lines on the screen of the Xiaomi smartphone

Please first try taking a screenshot of the screen and zoom in on the image in your Gallery to check if the abnormal lines are present.
If the screenshot captures the abnormal lines, please refer to the following methods to troubleshoot:
1. If the issue occurs only with a specific APP, please report the problem to the third-party APP developer for resolution. Additionally, try restarting the APP or restarting your phone to see if the issue persists;
2. If the issue appears on all pages, try changing the default theme or switching to a different wallpaper;
3. If the screenshot does not capture the abnormal lines, check for any system updates (update to the latest version). If updating the system does not resolve the issue or no new updates are available, back up your phone data to another device, then visit an authorized service center or request mail-in repair for further inspection and handling.