Shortcuts: Share Sheet cannot handle RAW photos

I have been trying to write a shortcut for my collection of RAW photos in the macOS Photos app, but keep getting stuck on the very first step. The shortcut fails on any RAW photo I select.

To test the problem, I've created a VERY simple rule that gets any item from the share sheet and displays the result:

If I select a JPEG or HEIC photo, it displays the photo as I expected:

But if I select a RAW photo, it displays an object of type "URL" which is the file path of the temporary directory for share sheet exports: 

That directory is empty.

The end result is that I cannot create any shortcut that does anything with RAW photos. For example, let's say I wanted to convert the processed RAW image to HEIC. If I added a Convert Image step, I get the error, "Conversion Error: Convert Image failed because Shortcuts couldn't convert from URL to Image."

At first I thought it might be the file format (Canon .CR3) or the size (50MB) of each file, but I went back to my earliest RAW photos that are much smaller (5MB) and the same problem occurs. I also double-checked to make sure that my iCloud Photo Library settings were set to store originals on my Mac, and it was. 

Anyone know what the issue is?