Memory leak then using QNetworkProxy on https

my app download small files many time. If it's don't use proxy - memory usage is stable, but if I call setProxy with proxy type QNetworkProxy::HttpProxy - i have stable increasing of memory usage. It's reproduced on Windows 10, and on ubuntu linux.
Project to reproduce this attached

On every click button - Memory usage increased about 1MB

To reproduce issue - write down https address of small text file here 

const QUrl url = QUrl::fromUserInput( "https://small page to test" );

and write correct proxy params here 

qNAM.setProxy(
QNetworkProxy(
QNetworkProxy::HttpProxy,
"host",
8000,
"user",
"password"
));

Important conditions - https and proxy set
Qt version 5.13.0