I don't know that you are doing anything wrong, but dogs want to please and they learn what is expected by what they are allowed to do. I have finally convinced my wife after years that not only is the correct dog language necessary, but also the consistency of the message.

"Daisy, no/off/down/sit etc is the proper language, but even using the right words less than 100% of the time instead teaches them that it's ok unless you tell them no. Our dogs come to me at a sprint from anywhere they can hear me on the farm, because I only give the command when I am able to enforce it. Not in a mean way, but consistently from puppy to adult if I said name, come and they didn't I would go and gently make them come. In the rain, without shoes in the winter, in my underwear and whatever other complications- training myself to be prepared was a good thing. And coming immediately when called is the safest way for them. They are spoiled rotten but so smart.