If the screen is grayed out, you may have set the sleep time/stop time for the healthy use of the mobile phone and turned on the switch that grays out the screen. After a limited time, the screen will turn gray and the application icon on the desktop will dim. It is recommended that you turn off this feature. Turn it off: Go to Settings > Healthy Use of Mobile Phone > Sleep Time/Stop Time, and turn off the screen graying switch.
2.
If the screen turns gray, you can turn on e-book mode. When turned on, the screen will turn gray for reading and text scenes. If you don't need it, you can turn it off. Closing mode: enter Settings, search, click E-book mode, and close E-book mode. If "e-book mode" is not found, your mobile phone does not support this function. Please check other scenarios.
3.
If the above troubleshooting still doesn't solve your problem, you can try to restore all the settings of your phone.