On Windows 8.1 client, the latest OneDrive updates has changed the heritance of the "’make available offline”.

Indeed, previously, all content I stored below my OneDrive Documents folder was automatically set as available offline because I set the parent folder (Documents) to do so.

Unfortunately since the last OneDrive update, thie heritance has been broken and you have to manually select one by one each new content to be kept available offline.

It seems this is not the only issue with the last updates.