I have faced an issue with my Starling for a few days (issue) and after some debugging attempts I decided the only way forward is to reinstall the latest version of the SDK (voxl2_SDK_1.1.1).

Following the steps discussed in another topic (topic) I attempted a "factory flash":

cd voxl2_SDK_1.1.1
cd system-image
./flash-system-image.sh -f

cd ..
cd voxl-suite
./offline-install.sh

adb shell

My VOXL2 was unable to fastboot automatically so I had to do a manual fastboot following this guide VOXL2 - How to force fastboot

After some attempts (was kind of tough to get it with 2 hands). I managed to start the flash but it got stuck here:

After letting it hang for ~45minutes I unfortunately had to cancel it and power cycle. At which point I was no longer able to discover the device either through adb or fastboot. At this point i considered my VOXL2 to be bricked and followed the following guide to unbrick it. For some reason after switching the VOXL to EDL it was not consistently discoverable in my host PC and had to do several attempts by rebooting both my host PC and power cycling the VOXL until I got it to succesfully flash. I tested the succesful image flash by doing an adb shell which connected.

The Problem
At this point I follow the afforementioned procedure to reinstall the SDK but I am having trouble to fastboot. I can now consistently discover the VOXL in both QDL and normal mode but whenever I attempt the fastboot procedure (and I assume it enters fastboot) I can no longer discover the device as either USB, adb or fastboot connection. Is there any other way I can tell my VOXL to fastboot on next boot? Do you have any suggestions on how to proceed?

Setup:
host: Ubuntu 20.04 (tested on Ubuntu 18 too)
starling power supply: 12V 3A (/w custom XT60 to XT30 connector)
USB-C connection: USB-C to USB-C on host (has worked without issues prior to the factory flash, attempted other cables too)