Does my dog can have breed puppies anymore?

Hello everyone!

I have a question that might sound strange, but I heard from some people that:

If my female labrador had a sex with a non breed dog then she can't have best breed puppies anymore even if she breeds with labrador male in the future.

It's something like that: https://en.wikipedia.org/wiki/Telegony_(pregnancy)

Thank you

not heard of this before ?

This is an old wives tale. Each litter is the product of its two parents.
Lab x Lab = 100% Labrador puppies.
Lab x Other breed = Crossbred puppies which may resemble either, or a mixture of both, parental breeds.

Absolute nonsense.