Bug? Empty variable in apk

Hi, I am not sure why, but in my app, the Live view works just fine, but when I create the apk and upload it to the mobile, the app gets stuck at the login screen with this solution:

while it works perfectly well with this (workaround) solution:

I repeat: the app works well with both solutions in the Live view, but the first approach breaks down in the apk.

Something to do with the “empty” variable…?

Instead of checking if they are empty try checking if they are equal to “null”.