Depending on the model and version number, apps on the Samsung device can send so-called pop-up notifications, which are displayed above all other content for a few seconds. If this is explicitly desired or not desired, the pop-up notification can be activated or deactivated for each app.

Android 10 (One UI 2.0)
Step 1:  Open the  Settings
Step 2:  Tap on  Apps
Step 3:  Tap on desired  App
Step 4:  Tap on  Notifications
Step 5:  Choose a  Notification category
Step 6:  Enable or disable  Show as pop-up
  1. Open the Settings
  2. Tap on Apps
  3. Tap on desired App
  4. Tap on Notifications
  5. Choose a Notification category
  6. Enable or disable Show as pop-up

Samsung Instructions