Tokens not appearing when dragged from Monster Compendium

So I purchased the MM so I could more readily use the tokens. Initially it worked fine - drag a monster and it's token appeared on the map. For some reason now it does not show the monster - just a blank portrait. Thus the entire reason for dropping $20 on the compendium seems wasted. I did go into the game settings and make sure that the compendium is shared with the players too, but that has had no effect. Is this a bug or is there a workaround so I can use the tokens that come with the monsters?

The problem most likely is an existing in-game version of the monster. The MM won't overwrite any changes to an existing character. This is desirable behavior. Suppose you've decided that goblins in your campaign use spears instead of scimitars, and can all cast minor illusion. You don't want a fresh drag from the MM overwriting your work. For one of the Monsters that is giving you problems, try deleting the current version from your campaign (plus any duplicates). Then drag in a new copy. You should see the proper token. You also should not need to enable compendium sharing for this to work. You personally should have the MM available to you in whatever game you have created. For things that players can access, (like classes, races and spells), you should have access to those in any game you are in, regardless of the purchases of the creator.