Filtering choices

I am conducting a survey that entails pulling data of household members from a list, for respondent to confirm if they are still members, and enter data of new members after. After this, I combine the two lists to a single household roster so that I can use it as choices after.
The problem is I am unable to filter this combined list --it gives me the combined list but with blank spaces in between.
I attach a sample of what I am doing.
Kindly assist
sample.xlsx (19.2 KB)