I am confused what triggers this message in my wishlist. Currently, I have many of the cards on the wishlist in ongoing trades, but only one of them is showing up with the icon and message: "this card is present in your ongoing trades. Click for details"

When I click the edit box for other cards on my list, and go to the trades tab, they are correctly showing as incoming ... they just don't get the icon.

I did try to search for this on the forum and couldn't find anyone else asking based on several keyword searches.

This has been mentioned a few times, but like you I can't seem to find the posts. I'm sure it's on Sebi's to-do list though.