I am also having this issue.
I ended up trying to update the OS using flashtool since I thought the mender instructions did not work as I was no longer able to ping the device and I still can not ping it.
The device shows up in dmesg like so:
[ 5386.088616] usb 2-1.4: new SuperSpeed USB device number 9 using tegra-xusb
[ 5386.111403] usb 2-1.4: New USB device found, idVendor=1d6b, idProduct=0103
[ 5386.111475] usb 2-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 5386.111523] usb 2-1.4: Product: USB Ethernet
[ 5386.111565] usb 2-1.4: Manufacturer: Luxonis
[ 5386.111606] usb 2-1.4: SerialNumber: t00000002
[ 5386.138498] cdc_ncm 2-1.4:1.0: MAC-Address: 8a:d8:3f:ad:b2:ac
[ 5386.141172] cdc_ncm 2-1.4:1.0 usb0: register 'cdc_ncm' at usb-70090000.xusb-1.4, CDC NCM, 8a:d8:3f:ad:b2:ac
[ 5386.460480] IPv6: ADDRCONF(NETDEV_UP): usb0: link is not ready
[ 5386.490781] cdc_ncm 2-1.4:1.0 usb0: 3750 mbit/s downlink 3750 mbit/s uplink
[ 5386.522772] cdc_ncm 2-1.4:1.0 usb0: 3750 mbit/s downlink 3750 mbit/s uplink
[ 5386.938777] cdc_ncm 2-1.4:1.0 usb0: 3750 mbit/s downlink 3750 mbit/s uplink
[ 5386.970839] IPv6: ADDRCONF(NETDEV_CHANGE): usb0: link becomes ready
Any updates would be appreciated on this matter if someone finds out what causes this.