Folder Action to Convert Image Format after AirDrop?

I often use AirDrop to move photos from my iPhone to my Mac, and I'd like to automatically convert any HEIC photos to JPEG. I created this folder action in Automator, and it works when a photo is dragged into the Downloads folder but not when it has arrived via AirDrop. Is there a trick to getting folder actions to work with AirDropped files?