have to keep downloading the same files again and again from iCloud to mac

If this question has been answered previously, please let me know, but I couldn't find anything. I recently got iCloud Drive, and I want to save my files on my MacBook Air so they are always available even without an internet connection. I click on the cloud icon to download my files, and they will be fine for a few hours or even a day. Then, the cloud icon appears again, and I have to download again or else I can't access my files without internet. So I download again. Even when I don't make any changes or add anything new, the cloud icon continues to appear every few hours. I so keep downloading the same files over and over, because without internet I can't access them despite being previously downloaded multiple times. This happens with large folders contains several GBs of data as well as small files only a few MBs. My OS is up to date. Is there a way I don't have to continually re-download all the time, or is this just how iCloud works? If that's the case, I'll cancel my subscription.