Help- Google Sheets as username/password database

I am currently developing an app for the Congressional App Challenge, and I have run into an issue. I am trying to use Google Sheets as a database for usernames and passwords, but something with the output isn’t working. For a test, I placed “test” in both the Username and Password columns, and a ListViewer so I could see what it retrieves. Displayed in the ListViewer is ( test test), but the “Is In List?” function always returns null unless I retrieve the exact same input from the list itself and feed it into that function. Even inputting ( test test) as a text block returns as null. Is there something I am missing?

Please show your relevant blocks and how you are setting data and getting data in google sheets