I live in central Illinois and have been having similiar problems but thinking it is because of the late frosts we have been getting....it has been getting warm early in the spring....which makes the buds come out on last years stems....then we get a frost and it is doing those poor buds in....I didn't have a single hydrangea bloom this year that bloom from old growth...and I even covered them with sheets to try and protect them but it didn't help....Mother Nature has been cruel to those!! The only one this year that bloomed is my Strawberry/Vanilla and that is because it blooms a bit later in the summer and on new growth....wishing there was a way to help save these from frost but it just the chance we take growing those in zone 6!!!
