Google sign in "Choose an account to continue" loop

I'm trying to implement the following packages with my Flutter app:

https://pub.dev/packages/permission_handler

https://pub.dev/packages/fit_kit

and I've done so by writing the following two functions:

Future<void> checkPermissions() async {
 var status = await Permission.activityRecognition.status;
 if (status.isUndetermined || status.isDenied) {
   Permission.activityRecognition.request();
}  else if (status.isPermanentlyDenied) {
   openAppSettings();
 }
}

Future<void> read() async {
 results.clear();
 await checkPermissions();
 for (DataType type in [DataType.STEP_COUNT, DataType.DISTANCE]) {
   try {
     results[type] = await FitKit.read(
       type,
       dateFrom: _weekBeginning,
       dateTo: _now,
     );
   } on UnsupportedException catch (e) {
     results[e.dataType] = [];
   }
 }
 dailyStepBuffer = 0;
 dailyDistanceBuffer = 0;
 for(FitData dataPoint in results[DataType.STEP_COUNT]){
   print(dataPoint);
   dailyStepBuffer += dataPoint.value.round();
 }
 for(FitData dataPoint in results[DataType.DISTANCE]){
   print(dataPoint);
   dailyDistanceBuffer += dataPoint.value.round();
 }
 setState(() {
   dailySteps = dailyStepBuffer;
   dailyDistance = dailyDistanceBuffer;
 });
}

The functions and packages work as intended on iOS, but for some reason, whenever I call read() on an Android device, it shows me this sign in screen, and when I click on my account, it does nothing and I get the error:

E/flutter ( 8211): [ERROR:flutter/lib/ui/ui_dart_state.cc(166)] Unhandled Exception: PlatformException(FitKit, User denied permission access, null)

I've gotten the OAuth 2.0 client ID using my SHA-1 fingerprint, added <uses-permission android:name="android.permission.ACTIVITY_RECOGNITION"/> to my AndroidManifest.xml file and added the following to my build.gradle:

implementation 'com.google.android.gms:play-services-fitness:19.0.0'
implementation 'com.google.android.gms:play-services-auth:18.1.0'

Unfortunately though, none of these appear to have solved the issue. I'd be extremely grateful if anyone could help me solve this, thanks!