Hello Nicholas. To disable OneDrive Files On-Demand - which is enabled by default starting with OneDrive build 23.066 - you will need to change your OneDrive settings manually. Files On-Demand allows your files to show up in File Explorer without it taking up any disk space until it is accessed. In my experience, this has caused compatibility issues or sometimes availability delays when a user is accessing files offline.
To disable it:
Click the OneDrive cloud icon in your taskbar.
Select the settings gear icon > Settings.
In the Settings tab, Uncheck the box entitled: Save space and download files as you use them.
After dismissing the warning prompt, select OK.
Your files will now download from OneDrive to your device and the on-demand behavior will be disabled. If you click “Download all files” and it simply opens a folder window without downloading, it is likely to due to this setting still being set to on.
Best regafcx,