I have an office 365 basic license for most users. I'm using it on Mac with OS 11.1 and latest OneDrive app.
The sync of the Sharepoint works fine for Word and Powerpoint files. However, Excel files are only synced from online->computer. Changes on the local version of the computer are not synced back. Moreover, in many cases it shows the file as "exist in the cloud" but trying to open it does not make it available offline locally. No error message is shown.
When choosing from the right click menu "always make available offline" the file switches to an icon with sync arrows but nothing happens.