I have some some dwarf and semi-dwarf Crapes,..no problems. But have not had success with the 'mini-dwarfs'...very disappointing. But, given that you say the bark is green, they should be all regrown by now. Some of mine looked dead but now completely recuperated. I know you are a zone lower, so give it some time. (Was ready to replace a Dynamite till 2 weeks ago!)

I have the mini dwarfs and they are the absolute last to leaf out in my z9a garden. The first year it happened I thought it was just dead but left it alone and sure enough, it caught up with the rest. They're also very slow to spread, I grow violet Fili, very pretty

I had the same experience with the dwarf bush. It leafed out SO LATE that I thought it died. We had a very cold winter and I thought it was lost but it did
leaf out from the bottom. I pruned it down to the low branches. It is doing well now.