Yuna featured vaguely Asian men (some could be Japanese, others are perhaps "East Russians"?) on an Asian woman, which is hardly "interracial"... but even if it qualifies it still isn't the kind of interracial Dob's patrons appear to like (hint: black men on white women).
Anyway, Dob didn't drop Yuna because of a "mistake", but because his patrons didn't vote for her.