corewebview2 select tag in flutter can't work correctly

My flutter project with Third party libraries webview_windows https://pub.dev/packages/webview_windows which is using corewebview2 can't work fine. Normally ,<select>...</select> tag should pop up a menu,but in my flutter project , when mouse clicke a select tag, nohting happen.I thing it's mostly because of the focus event. Every time the mouse clicked,flutter view get focus first,then the webview lose focus,and then flutter view lose focus and webview get focus finally, the focus change between flutter and webview.Is it the reason why select tag can't pop up a menu? if it is , I hope there is a method that can handle focus when the webview lose focus(to avoid webview lose focus or make some tag (like select..eg) work fine when webview lose focus).