In this video I will fix the Steam Deck fatal error that appears after factory reset and does boot loop:
"Fatal error: Steam needs to be online to update. Please confirm your network connection and try again."
iPhone tethering also works, but it will consume mobile data.
If you don't want to use tethering, try to create recovery disk:
https://help.steampowered.com/en/faqs...
There is also a good thread on this error:
/ fatal_error_steam_deck_wont_start_until_do...