New Xenon, and Spectra Xenon stuck in Listening, no USB serial

Troubleshooting
10

That's an important piece of info. If you are updating an Argon from anything before rc.25 to rc.25 or above, you also need to update the NCP (Network CoProcessor).
For that you need to download these files

And then you need to perform these commands in order
In DFU Mode (blinking yellow)

particle flash --usb system-part1-0.8.0-rc.27-argon.bin -v
particle flash --usb tinker-serial1-debugging-0.8.0-rc.27-argon.bin -v

In Listening Mode (blinking blue)

particle flash --serial bootloader-0.8.0-rc.27-argon.bin -v
particle flash --serial argon-ncp-firmware-0.0.5-ota.bin -v

For the Xenon you do respectively

In DFU Mode (blinking yellow)

particle flash --usb system-part1-0.8.0-rc.27-xenon.bin -v
particle flash --usb tinker-serial1-debugging-0.8.0-rc.27-xenon.bin -v

In Listening Mode (blinking blue)

particle flash --serial bootloader-0.8.0-rc.27-xenon.bin -v

You shouldn't need to unclaim/reclaim the devices, you can just set them up as if they were new, even if they are already claimed to your account.

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