iCloud documents offloading from my Mac

My documents on my desktop keep uploading themselves to iCloud and offloading from my computer to the point in which I can't access them if I am not online. I want to keep my iCloud drive on as I use these files on other devices but I want them to be downloaded into my computer as well. When I re-download them into my laptop they last there a good 5 minutes and then iCloud takes them again. This didn't happen before what should I do?