Filter Question - NFG

I am using filters in Network for Good to segment donors into groups by giving level over the last 12 months. I am using “Total household donations over custom date range” and when the list is generated, only one member of the household shows up. Why don’t both members (if applicable) show up on the list? The filter states household donations, so wouldn’t that include the donations for the entire household? I am attempting to capture them as Giving Units and not individuals, since that is how they give, but the other individual is showing up with $0 donated in the same custom date range, even if they were grouped in the household and checked as a co-donor at the time the gift was recorded. Or is there a better way this information could be extracted?