Huawei P40 Pro
My phone uses a large amount of mobile data
Solution 3 of 4: Automatic mobile data usage is turned on
You can set your phone to use mobile data automatically when the connection to the Wi-Fi network is weak. To turn automatic use of mobile data on or off, you need to turn on mobile data.
Press Settings.
Press Wi-Fi.
Press the indicator next to "Wi-Fi" to turn on the function.
Press More settings.
Press the indicator next to "Wi-Fi+" to turn the function on or off.
Slide your finger upwards starting from the bottom of the screen to return to the home screen.