iCloud documents once downloaded no longer downloaded

Hello,

I'm having issues with iCloud on my MacBook Air. My documents folder has been synced to the cloud for almost 1 year. All my documents used to be accessible immediately (downloaded). Now half of them are only in the cloud and I need to download then (click the little cloud button) before I access them. Its really annoying and it never used to be like this. I also access all my files from my work PC using iCloud Drive and it does not have this issue - all documents are still downloaded.

Can any one offer a reason this may occur and how I can go about making sure my MacBook keeps all my files on my device as well as in the cloud.

Thanks in advance!

Megan