QML application memory footprint grow when window change size

When I run QML application from qt creator on release

for example this quickcontrols2\contactlist 

and when I change window size(with mouse) application memory footprint grow to 300-500MB after some time.

All works fine when I change to sw render with

qputenv( "QT_QUICK_BACKEND", "software" );

it is better with Qt 6.0.1, but when I switch application to full screen, I can also see 200MB in task manager

It looks like huge memory leak, but where?