Hip dysplasia in dogue de bordeaux puppy

Good afternoon I'm new here and would really like some professional advice as I'm not happy with vets diagnosis.. my bitch had our 1st litter 8 weeks ago all 12 pups healthy happy and growing well.Had them all inoculated last Wednesday and was given a clean bill of health on all pups. Past 3 days 2 of the BIG boys have had the odd limp when walking and painful squeal when picked up on odd occasion.Not all the time and will run around play happily with mum and the litter all feeding well. Took to vet as a precaution and he returns (we not allowed in due to lockdown) claiming hip dysplasia as he can hear it clicking and puppy squeals when he manoevures. I have done normal joint checks and was ok but im.no vet..I'm not happy a puppy can be diagnosed at this age with HD they have 2 much growming to develop in a giant breed. Advised to under feed him to slow his growth which I always keep my dogs lean anyway but he is a big boy at 8 weeks weighing 10kg.. They are wanting full x rays and advise not sell the puppy so am at a cross roads as don't believe is a true diagnosis to.go from totally healthy to this problem in less than a week ??? No stairs no.jumping no.climbing allowed so isn't environmental but dies have 2 1/2 hour playtime with all siblings.100% will speak to buyers I would never hide a possible problem but am.i being made worry over nothing ?? How can HD be diagnosed at 8 weeks in such a large breed dog