Power recycling and Offline System Update only completes step 1 & 2

I did a factory default setting but it didn't work.

What age are the systems (End of 2017?) If they are enrolled in insider preview - withdraw them from the program first before further troubleshooting. If they are older consoles they are most likely out of warranty and would need to be looked at more closely
from a repair cost vs new purchase perspective.

Best regards

Sassan

Hi. I'm quite sure we got them late 2018 or early 2019. How can I withdraw from the Insider Preview program?

If you are still having this issue I just fixed mine. I removed the hdd from the xbox and hooked it up to my pc. Accessed the system update 1 partition and deleted all the files and reinstalled the hdd. Then took a flash drive
(any drive over 8gb will work) and formatted that to NTFS and extracted OSU1 to it and inserted it into the USB port on the xbox. Booting the xbox by holding for 15 seconds, the bind button on the side and the eject button and pressing the power button. The
console then fully went through with the system update. Afterwards i just had to redo the initial setup but all my games and saves were still there. Hope this helps someone else.

Unenroll old or unused devices from the Xbox Insider Program

• Sign in on any Xbox One console or Windows 10 PC with your Microsoft account registered in the Xbox Insider Program.
• Launch the Xbox Insider Hub.
• In the Xbox Insider Hub, navigate to Settings > Manage devices.
• Select the console (s) or device (s) you wish to remove from the Xbox Insider Program, then select Done.