handishooter--How far away were those coyotes that were doing the howling and barking? Could they have busted you and the howling and barking been warning barks and howls? If you drove your vehicle too close, they may have been watching you as you walked in.
How long did you stay on your stand? Maybe you aren't giving the coyotes enough time to come on in. I have found that this is the time of year when many coyotes up in North Dakota either come on in during the first 5 minutes or so or they come in way after a half hour or more have passed. If you have a quality bunch of land you are calling, I'd opt to stay for no less than a half hour, but probably would stay for 45 minutes or more.
What sequence of calls did you use? How long and often did you play the fawn in distress sound? How long and often did you play the coy dog sound?
In regard to that "coy dog" sound, I'm wondering if they are referring to the male coyote sound? Some folks call the male the "old dog" of the family and maybe the "coy dog" sound is just a male coyote sound????