You will have to explain a bit better, or with video/pictures.
Make sure you have updated the firmware on the unit to 2.5 version.
Export to usb key needs to be done using the special “export to mcx8000” button on the drive panel.
What is the result on the unit?
finally i’ve managed to make everything work… almost!! just got a bug but will open a new ticket for that
thanks a lot all of you