I just got my cube orange and have been experiencing the same issue. I am trying to flash px4 through QGC daily (tried on multiple devices and both on stabile and daily version).
Thank you for your reply. Could you be so kind and instruct me how to download QGC master? Is this the regular QGC or something else beside the daily build and the regular qgc? If it’s same as downloading from qgroundcontrol.com then I have already tried it.