If a character has at least 11 Rogue levels, they get the "Reliable Talent" class feature.
By 11th level, you have refined your chosen skills until they approach perfection. Whenever you make an ability check that lets you add your proficiency bonus, you can treat a d20 roll of 9 or lower as a 10.
What happens if you then Roll a Nat 1 on a roll with which you would add a proficiency bonus? Is it neutralized or is it a Critical Fail?