If you don't want to use S Pen Air Actions from the Flexcil app, go to device settings>Advanced features>S Pen>Air actions menu and select Flexcil from the App actions list and disable the option.
If you don't want to use S Pen Air Actions from the Flexcil app, go to device settings>Advanced features>S Pen>Air actions menu and select Flexcil from the App actions list and disable the option.