@Ellie96 Again, all the (so called) red flags have to be lined up for the algorithm to catch and prevent certain bookings. Though sometimes the system makes errors as well. They must all be there for this one, but haven’t been for your previous bookings.
This booking may turn out to be just fine, or it may be a bullet you want to dodge. No perfect way to know. You can just walk away from this guest and politely explain that unfortunately your hands are tied. Then someone else can come along and book the space.