In addition to the time, charge status and date, the Always on display of the Oppo smartphone also shows notifications, but unlike the lock screen, only the icons of the respective app are displayed.

If notifications on the Always on Display are not desired, the "Pure Screen Off" mode can be activated, in which only the clock is shown and all other information is hidden.

Android 10 | ColorOS 7.0
Step 1:  Open the  Settings
Step 2:  Tap on  Display & brightness
Step 3:  Tap on  Always-On Display
Step 4:  Enable or Disable  Display clock only
  1. Open the Settings
  2. Tap on Display & brightness
  3. Tap on Always-On Display
  4. Enable or Disable Display clock only

Oppo Instructions