What can I use in this sentence:
People who hold on to a belief despite evidence that disproves the belief are called ______.
"Freddy and his friends were ______, they were advocates for the Flat Earth Society, preaching that the Earth is flat like a mat in the hope of new proselytes."
Like dogmatists but specifically about a prior belief since disproven. I could use zealots or fanatics, but again they do not seem to cover the exact meaning I'm after, i.e., the active advocation of a disproven idea. I came across the term non-evidentialist but would prefer something without the negative prefix (if possible), and it is probably too wide a term. The word fundamentalists tend to have religious connotations, though it may fit as some beliefs can be advocated in a similar manner to religious fervour (hence the use of proselytes above). I quite like the word sheeple? Though again, not the right context. I'm wondering if the word I am after does not exist.