Other details are not close enough to tell for certain. I’m guessing a type of fleabane (Erigon) perhaps? If this is fleabane, I can’t tell which cultivar this is. Check out one in the showy fleabane (Erigeron speciosus). The ‘Azure Fairy” If this isn’t the showy fleabane, please make new post with closeup photo of the back of the flowers, leaves & flowers buds Best wishes!
Link for an image of ‘Azure Fairy’