Hey Paul,
Yeah, I'm using qt6-6.2.4-os2-20230214.zip with qt6webee-20230216.zip. I got your special libcn0.dll and put it in C:\usr\local\lib, rebooted, then started the QT6 Dooble, did a google search on 'Plimsouls Million Miles Away', double clicked on the YouTube video offered, Dooble disappeared and a triple beep was heard.
A trap file was created in C:\qt6\bin (where QT6 and Dooble resides) - attached.
Regards,
BTW - plays fine in QT5 Dooble...