if QtWebView::initialize() is used after QGuiApplication then warning is displayed QtWebEngine::initialize() called with QCoreApplication object already created and should be call before
If initialize() is used before QGuiApplication warning goes away, when run with Qt Creator it works but if deployed using windeployqt Webview does not work.
Attached example reproduces it.
use QtWebView::initialize() before QGuiApplication and run with QTC it works without warning. Now deploy the binary with windeployqt and run. Webview will not work.