IIF statement semantics Arcade

I’m trying to create a pop-up based on a conditional IIF statement and am struggling with the semantics of arcade. This is my code. (Note: I’ve tried 10 both in and not in quotes)

IIf(IsEmpty($feature["PERCENT_A"]), "10", $feature["PERCENT_A"])

Once I base my pop-up on this expression, it looks like the false condition is working but the true condition is not; or else the popup is still just displaying my PERCENT_A field and applying no conditions to it.

I’m working in arcgis online and in the pop-up contents settings I’ve selected Display: ‘A description from one field’ and then selected my saved expression from the dropdown.

IIf($feature["PERCENT_A"]>0, $feature["PERCENT_A"],"10")