The FIRST time you use the Sage you need WiFi on and to have a Kobo account logged in (can use fake email or real, if you don't go to Kobo site and add details and buy books the email is never used. No payment method needed).
Then it downloads the Nebo handwriting recognition. That was failing a couple of weeks ago so I used the files off a working Sage.
The Elipsa didn't seem to need to do this. So try using the FW file here
https://pgaskin.net/KoboStuff/kobofirmware.html
for 4.32.x which is allegedly same for Elipsa and Sage.
Direct linkhttps://kbdownload1-a.akamaihd.net/firmwares/kobo8/Apr2022/kobo-update-4.32.19501.zip
I have 4.32.19501 on all my Kobos as I found 4.33.x buggy. Possibly that actual file.