I have Buddleia (that I struggle with, as we are on the northern edge of its range - zone 4) but the leaves of my mystery bush are not as long or pointed as the regular buddleia. The leaves are also thicker on the mystery bush. The flower clusters are not as elongated, tapering to narrow tips as I see in most buddleia photos.
This bush was on the property when we moved here and is planted with a lilac, making them look like one large bush. The lilac leaves are much wider and pointed though.
I have some photos showing the size of the bush (to the right of our screen tent) and some closer shots (some with butterflies), in the hope that someone may know what it is. Perhaps some different species of Buddleia, Lilac or ???
Thanks for any help or ideas,
John