问数据绑定-找不到BR类

EN

import android.databinding.BaseObservable;
import android.databinding.Bindable;
import com.android.databinding.library.baseAdapters.BR;

public class MyViewModel extends BaseObservable {

    public MyViewModel() {
        mStateText = "DEFAULT_TEXT_123";
    }

    @Bindable
    private String mStateText = null;

    public String getStateText() {
        return mStateText;
    }

    public void setStateText(String stateText) {
        mStateText = stateText;
        notifyPropertyChanged(BR.stateText);
    }
}

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:bind="http://schemas.android.com/tools">

    <data>
        <variable
                name="viewModel"
                type="my.org.MyViewModel "/>
    </data>

...


        <Button
                android:layout_width="200dp" android:layout_height="wrap_content"
                android:layout_row="1" android:layout_column="1"
                android:id="@+id/system_state_btn"
                android:text="@{viewModel.stateText}"/>

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        MainStatusBinding activityMainBinding = DataBindingUtil.setContentView(getActivity(), R.layout.main_status);
        activityMainBinding.setViewModel(new MyViewModel());
        activityMainBinding.executePendingBindings();

        View rootView = inflater.inflate(R.layout.main_status, container, false);
    ...
    ```
.

What is wrong with my setup that's causing IntelliJ to not recognize the class exists? Note, this fails for me when building on the commandline, so it's not specific to IntelliJ.

IntelliJ: 2020.1

Gradle wrapper: 6.3

android build tools: 28.0.3

android gradle plugin: 3.5.0

  [1]: https://www.journaldev.com/20292/android-mvvm-design-pattern