Rightangled interview questions

I was sent a link to a GorillaTest assessment, one of the screening questions was - and I quote - "Are you native British, or fluent in English from either Spain, Italy or Greece?" You can be fluent in English but not from those countries. This question has no bearing on one's right to work in the UK and was not mentioned as a job requirement in any capacity, but if you answer no, you cannot proceed with the assessment. When I emailed them (twice) for a simple clarification, I did not receive a reply. Fair enough if this was a hidden requirement but it was not clear in the job description at the time.