This is a good example of a user case that perhaps hasn’t appeared in testing.
I suggest you contact the team at help@monzo.com so they can better advise (we don’t get told all the nitty gritty details about fraud prevention on here!)
My gut feeling says it is just to verify you are a real human, but it would be best to email them
Sorry you’ve had this bad user experience - if it’s any consolation this will be noted and improved
So I think we can improve on this in terms of UX, perhaps with some kind of link to further questions or to direct you to us if there’s an issue. Open to all suggestions!
However with the actual verification itself, I think (but am not 100% sure) that Deaf Voice wouldn’t cause a problem. It might flag for a manual approval, but so do other videos for a myriad of different reasons. It wasn’t that long ago that we had to manually approve most/all submissions, so instances like this were just part and parcel - I certainly recall doing approval on submissions with deaf users in the past.
Regardless, we have manual procedures too if there’s a reason why the first procedure can’t be done.