IOS: Firebase Phone Authentication stops working suddenly in test flight - ios

Question

I am working on a flutter application that uses Firebase Phone Number Authentication (SMS OTP). It is working perfectly on Android but having issues with the iPhone. I am testing with a real device. I am able to login with the phone number several times after installing the application. But after some time, I am not able to login with the same mobile number and it asks me to check the number correctly. The sim is on the same phone that I am testing in. The phone login is not working in a simulator or real device while debugging and hence I am having trouble figuring out this issue. Has anybody experienced such weird behaviour before? I am using flutter 1.12.13+hotfix.9 and firebase_auth 0.15.3+1 version. Any help would be appreciated. Thank you.
_verifyPhoneNumber(BuildContext context) async {
final FirebaseAuth _auth = FirebaseAuth.instance;
await _auth.verifyPhoneNumber(
phoneNumber: phoneNumber,
timeout: Duration(seconds: 0),
verificationCompleted: (authCredential) =>
_verificationComplete(authCredential, context),
verificationFailed: (authException) =>
_verificationFailed(authException, context),
codeAutoRetrievalTimeout: (verificationId) =>
_codeAutoRetrievalTimeout(verificationId),
// called when the SMS code is sent
codeSent: (verificationId, [code]) =>
_smsCodeSent(verificationId, [code])); }
_verificationComplete(AuthCredential authCredential, BuildContext context) {
FirebaseAuth.instance.signInWithCredential(authCredential);
if (!smsCodeSent) handleLogin(authCredential);}
_verificationFailed(AuthException authException, BuildContext context) {
showDialog(
context: context,
builder: (_) => AnimatedDialog(), // SHows diaglog box with check your number error message);}
_smsCodeSent(String verificationId, List<int> code) {
smsCodeSent = true;
_smsVerificationCode = verificationId;
smsOTPDialog(context) }
_codeAutoRetrievalTimeout(String verificationId) {
// set the verification code so that we can use it to log the user in
_smsVerificationCode = verificationId;}
smsOTPDialog(BuildContext context) {
Navigator.of(context).push(
_createRoute(userPhoneNumber, _smsVerificationCode, _fullname.text));}

Answer 1

You should get your number setup inside the phone authentication sign method as a test phone number. Firebase Auth will block your phone number from using the services when it detects that your phone number is calling the services repeatedly. They flag it then block it for almost 4hours. Phone authentication has a rate limit of around 5 calls per hour for every phone number.
Try checking that out.