Has the setting to disable icon frames been removed on the Galaxy S10 lineup?
This seems to be a setting that started in Oreo related to Adaptive Icons.  You now need specific themes to remove the border.

Per the following link:


  If you don't want borders, go to settings>wallpaper and
  themes>icons>download and find an icon pack with no borders.


https://androidforums.com/threads/why-is-there-no-option-to-remove-icon-frame-borders-on-the-new-android-pie-update.1295501/