So, based on what I’ve seen elsewhere, Sayoc’s family says he has no Native ancestry and they don’t know why he’s claiming otherwise. (His ancestry is Italian on his mother’s side and Filipino on his father’s side.)
My guess is that since this guy is living up to every terrible right-wing loon stereotype, he was pretending to be Seminole in order to drum up customers for his failing businesses, exactly the way right-wingers imagine left-leaning people dishonestly embracing minorities for selfish reasons.