I had such player at my table but it was more that they could ignore what they knew. So they still were doing perception checks and I was still responding but randomly, without saying it.

Once, for a critical failure on a perception check, I said they saw the lord was too bright, too clean, and wait are those scales? Could be a dragonborn or even more? They spend the full enquiry rejecting the possibility to have a dragon in disguise. Sad for them.