Tasks that come from the App Reminder are displayed by default in the calendar of the Samsung device. Alternatively, we can hide the display of the tasks, in which case we need to disable the App Reminder in the App Events.

Android 10 (One UI 2.0)
Step 1:  Open the  Calendar -App
Step 2:  Open the  menu
Step 3:  Tap on  App events
Step 4:  Enable or disable  Reminder
  1. Open the Calendar-App
  2. Open the menu
  3. Tap on App events
  4. Enable or disable Reminder

Samsung Instructions