iOS App Clip Prefix Matching Not Working

App clip cards are not being displayed correctly according to the url prefixing documentation which states:

"The system then chooses the App Clip experience with the URL that has the most specific matching prefix."

This video also outlines the same strategy for invoking different app clip cards with a matching prefix (start video at 12:46).  

I have the following two advanced app clip experiences associated with my app: 

https://example.com/card1 -> opens correctly
https://example.com/card1/subcard1-> opens same card as above

Even though the second experience has a more specific url, it's still opening the app clip experience for the shorter url.

Both app clips were submitted over a week ago at the same time, so I don't believe it's a propagation issue.