0.561725 gphoto2-port-usb(1): USB device (vendor 0x4b0, product 0x108) is a mass storage device, and might not function with gphoto2. Reference: http://www.linux-usb.org/USB-guide/x498.html
I think that it was mounted as disk already makes it not accessible to sierra mode.
The trace has:
0.561725 gphoto2- port-usb( 1): USB device (vendor 0x4b0, product 0x108) is a mass storage device, and might not function with gphoto2. Reference: http:// www.linux- usb.org/ USB-guide/ x498.html
I think that it was mounted as disk already makes it not accessible to sierra mode.
Please just use it as mass storage device.