Google IMA webview is not showing when used inside

In short: We use reacte native on android and use the native VideoView to show videos with ads using the Google IMA SDK for android. The video plays, the ads play, but the Webview containing "read more" and "skip ad" is not visible. It's added to the view hierarchy, but it's size 0,0 and it has no children. When I use the exact same code in a native app. Everything works as expected.

Some more context:

The video player / google ima sdk integration is copied straight from the google ima example app.
When the component is placed in a native anroid app everything works fine.
When inspecting the view-hierachy it's clear the webview is added and it's size is 0,0
When adding a native webview myself it's is rended perfectly fine.

Relevant code from the React Native component:

@SuppressLint("ViewConstructor")
public class ReactVideoViewWithAds extends FrameLayout implements
    LifecycleEventListener {

private VideoPlayerWithAdPlayback mVideoPlayerWithAdPlayback;
private RelativeLayout mCompanionAdSlot;
private VideoPlayerController mVideoPlayerController;

public ReactVideoViewWithAds(ThemedReactContext themedReactContext) {
    super(themedReactContext);
    createViews();
    themedReactContext.addLifecycleEventListener(this);
}

private void createViews() {

    FrameLayout.LayoutParams companionAdLayoutParams = new FrameLayout.LayoutParams(
            FrameLayout.LayoutParams.MATCH_PARENT,
            (int) (50 * getResources().getSystem().getDisplayMetrics().density));
    companionAdLayoutParams.gravity = Gravity.CENTER_HORIZONTAL;
    mCompanionAdSlot = new RelativeLayout(getContext());
    mCompanionAdSlot.setBackgroundColor(Color.BLUE);
    addView(mCompanionAdSlot, companionAdLayoutParams);

    //player with ad playback
    FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(
            FrameLayout.LayoutParams.MATCH_PARENT,
            FrameLayout.LayoutParams.MATCH_PARENT);
    mVideoPlayerWithAdPlayback = new VideoPlayerWithAdPlayback(getContext());
    addView(mVideoPlayerWithAdPlayback, layoutParams);


    initPlayer();
}

private void initPlayer() {
    mVideoPlayerController = new VideoPlayerController(
            getContext(),
            mVideoPlayerWithAdPlayback,
            null,
            null,
            "nl",
            mCompanionAdSlot,
            null);
}

This question had the solution in a comment

When adding views dynamically in a native component it seems you need to manually trigger a layout cycle in order for react-native to pick up on the changes. (perhaps related to react native updating it's shadow-view)

 @Override
    public void requestLayout() {
        super.requestLayout();
        post(measureAndLayout);
    }

    private final Runnable measureAndLayout = new Runnable() {
        @Override
        public void run() {
            measure(
                    MeasureSpec.makeMeasureSpec(getWidth(), MeasureSpec.EXACTLY),
                    MeasureSpec.makeMeasureSpec(getHeight(), MeasureSpec.EXACTLY));
            layout(getLeft(), getTop(), getRight(), getBottom());
        }
    };