Qt's QFileDialog displays slowly when using the<input>tag of H5 to select local files in QML's WebEngineview

I use the QML ‌WebEngineView‌ to load an HTML page, and the HTML ‌contains‌ an <input> element to choose a local file. ‌Occasionally‌, the ‌QFileDialog‌ takes more than 5 seconds to appear. Before the dialog is shown, the program ‌freezes completely‌, and if I ‌click repeatedly‌, it prompts me to ‌terminate the application‌ or continue waiting.

cpu: Intel i7-1225U

memory: 16.0GB