I have had Pavlovskaya chicks before. I hatched them from purchased eggs. I still have a young 8 month old cockerel. They are beautiful birds. I had 3 from my hatch, but the 2 females died. One at 6 weeks and the other at 8 weeks. No signs of illness. It seems to be an issue with them here in the southern states. Not sure what they die from as not autopsy was performed.
I also have 4 White Pavlovskaya chicks direct from Green Fire Farms in FL, just over 2 months old. I can't tell their sex as yet but should be able to very soon.
Good luck with your hatch. I wish I had that many in my incubator.