How to fix flutter widget flickering?

I'm trying to load an image from firebase storage to my app however I have this weird issue where the profile page(where this image is loading) keeps flickering. The image is loading fine however the whole widget keeps flickering. I have narrowed the issue down to the setState() called within the function getProfilePic() after some debugging, however I do not know if it's the function itself or my call to said function.

P.S there is no issue with the fileURL or picRef.getDownloadURL() as I've tested this with a random internet image as well and got the same flickering.

class profileTab extends StatefulWidget {
  @override
  _profileTabState createState() => _profileTabState();
}

class _profileTabState extends State<profileTab> {

  User user = FirebaseAuth.instance.currentUser;
  String _image = "https://picsum.photos/250?image=9";

  Reference picRef = FirebaseStorage.instance.ref().child(FirebaseAuth.instance.currentUser.uid);

  Future<Widget> getProfilePic() async {
    await picRef.getDownloadURL().then((fileURL){
       setState(() {
         _image = fileURL;
       });
    });
  }

  @override
  Widget build(BuildContext context) {
    getProfilePic();
    return StreamBuilder(
      stream: FirebaseFirestore.instance.collection('users').doc(user.uid).snapshots(),
      builder: (context, snapshot){
        if (snapshot.connectionState == ConnectionState.active){
          return ListView(
              children: <Widget>[
                SizedBox(height: 100.0,),
                CircleAvatar(
                  radius: 100.0,
                  backgroundColor: Colors.lightBlueAccent,
                  child: ClipOval(
                    child: SizedBox(
                      width: 180.0,
                      height: 180.0,
                      child: Image.network(_image,fit: BoxFit.fill,),
                    ),
                  ),
                ),
                SizedBox(height: 30.0,),
                Center(child: Text("Name: " + snapshot.data.data()['name'],textScaleFactor: 3.0,)),
              ]
          );
        }
        else {
          return CircularProgressIndicator();
        }
      },
    );
  }
}