The screen resolution can be changed manually if you are not happy with the "smart resolution", which is set by default. The "Smart resolution" reduces the display resolution to save battery. If you wan to adjust the resolution manually,the choice is HD and FHD +. 

Android 10 | EMUI 10.0
Screen resolution -  Open the  settings
Screen resolution -  Tap on  Display & brightness
Screen resolution -  Tap on  Screen resolution
Screen resolution -  Activate or deactivate  Smart resolution , or choose  HD+ / FHD+
  1. Open the settings
  2. Tap on Display & brightness
  3. Tap on Screen resolution
  4. Activate or deactivate Smart resolution, or choose HD+/FHD+

Huawei Instructions