Test an Action does not use test Event payload

I noticed that when testing an Action, it does not seem to use my entered email address. If it does, it is not logging properly. If I enter user_a@gmail.com in the Event payload, the log always uses my personal email. Is this intended? Am I misinterpreting this?

Furthermore, what is the Test actually doing? We noticed we were getting 404 errors when attempting to login, but when we ran the Action everything passes. The Action was literally broken but the Test ran fine.