Adwidget google_mobbile_ads flutter banner hangs camera on Android but not in iOS

Question

I was using google_mobile_ads plugin to display ad as suggested in this codebook. I tried this on my existing app with camera and tflite plugins to display a banner ad. I am able to display the ad successfully, but the camera completely hangs(in emulator, oneplus5, samsung m31). In the emulator, I am unable to move the camera around in virtual environment and phone cameras drop to probably 1fps and feel stuck. The problem remains even when a live ad isn't loaded and nothing is displayed. The same code built on iOS doesn't seem to have any issue.

As soon as I remove the Adwidget, and add a simple Text, the problem goes away. Following is my widget build code:

Widget build(BuildContext context) {
    Size screen = MediaQuery.of(context).size;
    return Container(
        child:  Stack(
          children: [
            Camera(
              widget.cameras,
              _loadedModel,
              setRecognitions,
            ),
            Container(
                width: screen.width,
                height: _ad.size.height.toDouble(),
                child:Container(
                    // child: Text("XZCXZCZXCXZC"), // Uncommenting this and commenting Adwidget code makes the hang/lag issue go away
                  child: AdWidget(ad: _ad),
                    width: _ad.size.width.toDouble(),
                    height: _ad.size.height.toDouble(),
                    alignment: Alignment.topCenter,
            ),)
          ])
    );
  }

And following is my bannerad initialization code written in initState (similar to the cookbook)

_ad = BannerAd(
      adUnitId: AdManager.bannerAdUnitId,
      size: AdSize.banner,
      request: adRequest,
      listener: AdListener(
        onAdLoaded: (_) {
          setState(() {
            _isAdLoaded = true;
          });
        },
        onAdFailedToLoad: (ad, error) {
          // Releases an ad resource when it fails to load
          ad.dispose();

          print('Ad load failed (code=${error.code} message=${error.message})');
        },
      ),
    );
_ad.load();