Not-See

A person who believes they are doing something right or good while being oblivious to the flaws in their thinking, belief, or execution is often described as having a "blind spot" or exhibiting
"confirmation bias" in their thinking, where they selectively focus on information that confirms their existing beliefs and disregard contradictory evidence.

Other relevant terms depending on the context could include:
"Self-deceived":
When someone is actively misleading themselves about their actions or motivations.

"Dunning-Kruger effect":
A cognitive bias where people with low ability overestimate their own competence, often leading to a lack of self-awareness about their mistakes.

"Illusion of superiority":
A related concept to the Dunning-Kruger effect, where someone believes they are better than others, even when evidence suggests otherwise.

"Cognitive dissonance":
When someone holds conflicting beliefs or behaviors, which can lead to them rationalizing their actions to maintain consistency.

They are so blind to their fallacies, I would call them a “Not-See”