Android Google Sign In is flashing a small empty white box while signing in a user
Try this not sure:It is nothing but just a label you have applied to that activity in manifest, remove this from that activity
android:label="@string/app_name"OR check you layout file does there exist some empty view which is getting visible.Thank you.
i think you haven't add
apply plugin: 'com.google.gms.google-services'
outside the dependency section.also add classpath in project level gradle file
classpath 'com.google.gms:google-services:3.1.1'
update the google play services ,Android platform tools and android build tools.sometimes it happens due to the version conflicttry this,but i'm not sure about this
I guess you have used Button view in XML and then you are casting to com.google...SignInButton , due to his empty box is shown for while. Try changing XML view to com.google...SignInButton .