I was trying to help a customer with a Mac, she's using Sonoma 14.5 if that matters. Her iCloud settings apparently got her in a position where her Desktop and Documents folders are being redirected ...

Is there a best practice on how to use OneDrive and iCloud Drive on a macbook with limited disk space, that prevents sync issues? I know little about mac and I'm helping someone who knows even less.

The previously separate iCloud "Documents & Data" service will automatically be merged into Apple's iCloud Drive in May 2022 — but users will have to take steps to continue seeing their documents.