We're having issues getting Sign in with Google to function on TestFlight (not experiencing these issues on iOS Browser) with user unable to be authorised and proceed to logged in screens of our app.
Below are the three sign-in methods tested and the exact results for each.
Button 1: Default
Standard Google Sign-In button (Google JavaScript SDK) embedded in the frontend.
Uses the normal OAuth browser redirect flow.
Auth URL: https://accounts.google.com/o/oauth2/v2/auth?...
Sometimes disallowed_useragent error.
Other times a 400 invalid_request error.
In most cases the callback is never triggered inside the wrapper.
Appears that the wrapper does not retain cookies/session data from the external Google window.
Button 2: Custom
Custom button calling Google OAuth through our own redirect handler.
Explicitly set a custom user-agent to bypass disallowed user agent logic. Later removed user-agent override entirely for testing. Added multiple ATS (App Transport Security) exceptions for Google domains. Added custom URL scheme to Info.plist for OAuth redirect.
Changing the user-agent had no effect.
ATS exceptions + scheme support verified and working.
Redirect still fails to propagate tokens back to the WebView.
In tests a few weeks ago we got to Google’s login page, but it never returned to the app with a valid code. Now we are consistently getting disallowed_useragent error.
Button 3: Default
Same as Button 1 however tested outside of Vue.js with just plain JavaScript. Added new Google domain exceptions and updated redirect URIs.
Behaviour matches Button 1
Google account selection sometimes worked, however now consitently disallowed_useragent error
- Additional Technical Attempts
User-Agent Modifications
Set UA to standard desktop Chrome → no effect.
Removed UA override → no effect.
ATS / Domain / Scheme Configuration
Added:
accounts.google.com
.googleusercontent.com
*.googleapis.com