Invalid argument: Instance of 'GroupModel'

I want to update user profile where user is:

class UserModel {
  final String uid;
  String name;
  List<GroupModel> group;
  LocationModel location;
  String profileImageUrl;
}

and this is the button:

TextButton(
                onPressed: () async {
                  reBuild = true;
                  UserModel updatedUserInfo = UserModel(
                    name: widget.nameController.text,
                    profileImageUrl: widget.userInfo.profileImageUrl,
                    group: widget.userInfo.group,
                    location: widget.userInfo.location,
                    uid: widget.userInfo.uid,
                  );
                  await updateUserCubit
                      .updateUserInfo(updatedUserInfo)
                      .whenComplete(() {
                    Future.delayed(Duration.zero, () {
                      Navigator.of(context).maybePop(widget.userInfo);
                      reBuild = false;
                    });
                  });
                },
                child: checkText(false),
              )

but I have the error Invalid argument: Instance of 'GroupModel'and I dont know why because group wants a List and widget.userInfo.group is a List Can you hel me?