This issue comes from the GMA plugin: https://github.com/googleads/googleads-mobile-flutter.

There is noticeable lag when webviews displayed using hybrid composition are placed in a scrolling view. The performance is significantly worse on android api < 10 and lower end devices, but it has been seen on higher API levels as well.

The GMA plugin uses hybrid composition on Android. Virtual display is not a viable workaround.

Reproduction details can be found in the original issue: googleads/googleads-mobile-flutter#269