StartPage not called for Windows on graphics object?

I just tried to print via MBS DynaPDF Plugin on Windows.

We get a print graphics object via OpenPrinterDialog functions and use the handle to let the plugin draw PDF there.
But it seems like the Win32 StartPage function is no longer called by Xojo.

Reported as Feedback case 46436.

If asked via GetDeviceCaps, the size of the page is reported as zero.