Firebase auth reports <keychain-error> on iOS while working fine on Android (Flutter)

Trying to use firebase auth on flutter (email/password auth)

      try {
      await FirebaseAuth.instance.signInWithEmailAndPassword(
          email: txt.text,
          password: pass.text,
      );
    } on FirebaseAuthException catch (e) {
      if (e.code == 'wrong-password') {
        ScaffoldMessenger.of(context).showSnackBar(SnackBar(
          content: Text('Wrong password'),
        ));
      } else {
        ScaffoldMessenger.of(context).showSnackBar(SnackBar(
          content: Text(e.code),
        ));
      }
    }

Getting Firebase Auth Exception with error code 'keychain-error'

Auth method not matters, i'm getting same with Google auth

moreover: if i will enter wrong password it will report wrong password error, so everything is fine with contacting firebase server (i've installed firebase into project properly)

Same code works fine on Android