Agree with this 100%. I always tell puppy buyers to always verify health test results with OFA website. And even the dog pedigree to check at least at vizsla data base. I remember a few years ago a post in FB where a vizsla pedigree showing famous breeding lines but the serial number were of a different breed. So be careful out there.I know a couple of breeders have posts, that AKC does not proof the their ads for puppies.
That any breeder could list themselves as being a breeder if merit, and list health clearances, and club involvement. It's not always true.
So you would still need to verify, any information posted on the AKC Market place.
OFA has a website, that makes checking health clearances very easy.
You can also send the area vizsla club a email, to see if the breeder is active with them. AKC also has a place online to search for breeders of merit.
Even with all that said, I would still ask the breeder referrals list from a Vizsla club.