[Qt5.15.4][QWebEngine]QWebEnginePage::print() function printing a grey paper while printing a PDF in Qt5.15.4

QWebEnginePage::print() function is printing a grey paper while printing a PDF in Qt5.15.4 &  Qt5.15.6

Attaching the test application along with the page printed(test_pdf.pdf). 

The test application does the following:

1. create a QWebEngineView with the following setting : PluginsEnabled, FullScreenSupportEnabled, PdfViewerEnabled.
2. load a pdf file to QWebEngineView 
3. print the pdf file invoking 'QWebEnginePage::print()'

The page printed is a grey paper.

Additional Info:

The same test application is printing proper page in Qt5.15.2.