User email freeze the login

HI, this has happened at least 5 times and it is causing me to have to re-do my app, losing a few days of development time.

My APP configuration is for user to sign in with email. I have one sheet called “User” to accept registration. Attached is a portion of the user registration. The condition for sign-in screen visibility is set to if the person’s name is empty.

During the first time a user signs in, the registration form is displayed. Upon registration, the name field will be populated and the screen will change to their profile, making the registration form invisible. Sometimes this process does not happen.
When I look at the User’s sheet, the signed in email, in this case, is duplicated with the first time row just the email and the duplicated one has all the filled up data. The reason the login screen hanged is due to the fact that the first sign in email is the active email and the name field is false.
I hope it makes sense.
How can we prevent the email from being captured before form is being filled up? In the APP: Logins sheet I can see that the login of the same email has been recorded. For some reason, it is also recording this first instance in the USER sheet, which causes this freezing issue.

Much appreciated any words of wisdom. Thank you.