I just tried your testsite on mobile and tablet and it doesn’t work well at all for me, or I don’t understand the mechanism – sorry to say 
- The first problem is it tries to open the preview on long press. Trying to press slightly shorter, doesn’t work of course and opens the topic.
- And then it simply does not move after pressing drop either
This is what I’m getting: (I’m targeting the top card titled : “Getting started Guide: App Devs”)
I’m testing on iOS (18.7) – could be a version issue, so I wonder if you have tested on iOS too, or only Android so far?