Whats the trick to drag and dropping monsters?

I find that if I drag and drop monsters from the sidebar I get the right icon and so forth but its unreliable.  I would say most of the time it doesnt work. If I drag and drop directly from the NPC/character sheet it always works but it doesnt use the icon but the picture of the character instead.   Wondering if there is somethign I am doing wrong here?  Or what is the best way to set mobs up quickly.  I cant rely on drag and drop during games at this stage.

If you drag from the Name, it should always work the same.  The avatar should only show up as a token if you don't have a default token assigned.  I don't believe dragging from the icon at left will do anything on the VTT (you drag from the icon to reorder items in the journal's folders).

To add, Compendium Monster Entries with Token art will create and place a Default Token on the Tabletop when dragged onto it .

Actually, it was me.  I was dragging it using the re-sort button (the three horizontal lines).  When I dragged it using the character it works.  Though sometimes there is a delay but I hazard to guess its my connection (or general latency).  Thanks for the advice.