If you notice that the icons on your Huawei P20 Pro are very large and the layout resembles Windows Mobile rather than Android, you have probably activated the Simple Mode in the Android settings.
This mode reduces the interface to make the phone as easy as possible to use. This will look something like the following: If you have inadvertently activated this mode and now want to return to the old view, please proceed as follows:
1. Open the smartphone settings
2. Navigate to "System"
3. Open "Simple mode" and deactivate it afterwards. This means that the icons will no longer be displayed in large size, but in the old normal size again.
You have successfully deactivated the Simple Mode on the Huawei P20 Pro.