During Easter I had something similar happen to enrobed marshmallows. The first round was good, we did a second round and hey looked good but quickly went white after setting up. We let the machine run a while longer, and tested again and we were fine. We posited that we were not really ever fully in temper, that seeding had not totally occurred and while we got a fluke good batch, the majority needed more time to settle into a temper.
You can re-temper and coat them twice but that's going to give you one heck of a thick shell. I really doubt that the bloom will come through. Blooming doesn't really operate like that afaik.
Good luck and sorry to hear about this, nothing worse than doing a production run of something to find out an endemic problem with it all.