Action flow check does not work after Login

Hi, I am new on Flutterflow. I have taken over an existing small project. I just wanted to add an additional action in the action flow when users press the Login button. This first action should check a value in my Firestore users collection. It looks straightforward so I thought I give it a go.

So what's the problem. We allow users to login with just their email address. When they press the Login button they get an email with a link which allows them to enter the app. However, I want to check first if the email address exists in our Firestore users collection. I do that with a simple Count function. But the logic is just not working.

I tried testing in Testmode and Run mode but nothing happens. Also tried testing within Apple's TestFlight. But nothing happens either.

What am I doing wrong or is there a way to debug the action flow?