I understand that Gray Goose but to replace 2018 queens with 2019 queens and then again a month later replace those 2019 queens on 10 hives seems a bit to much.
I would agree, if several hives with same source queens are on the 2nd or 3rd replacement, in the first year, that does not bode well.
there is likely something else going on. have you treated for Mites, what is the count? Possibility the first round was poorly mated. Also possible the original queens have virus of some sort, passed to the daughters. I would not panic but this is a cause for concern, if the queens are failing rapidly then at some point like, winter, they will not be able to find drones to mate. Maybe call the source/breeder and ask what they think is up. If a 3 rd round is started, I would replace some of them with "new, different source queens" if they also have the same issue it could be environmental, if not then it is the stock, perhaps. It is difficult to determine from a distance, I would definitely keep track of it. For me the last time I lost 4 of 5 newly mated july queens by late aug it was virus load and the hives perished by December. There is some evidence to suggest some of the virus is passed via body fluids. Varoa now vector like 9 different virus. be a sleuth, keep notes, get some new queen before the breeders stop for the year, if you feel that is what is needed. do some counts, treat if you are inclined. this indeed sounds odd. This year I have not had a queen replaced, knock on wood. Think on the "Why" and the answer will come easier.
GG