Hi triplebob,
Thanks for using Microsoft products and posting in the community, I'm glad to offer help.
According to your description, I've tested on my side, for folders, although we can make them available offline, the folders may not be visible to your device or external storage, they are only available within
OneDrive app, I have checked File Manager but I didn't find any folders even if I have made them available offline.
As a workaround, if the folder contains a lot of files, so you don't want to download each file manually, you can try to log into your OneDrive via a web browser, and then download the folder as a ZIP file, and then unzip
it to get all the files at once.
I can understand that this may cause a lot of inconvenience, and I'd like to suggest you vote for the following idea or post a new one in UserVoice, it is the best way to let the relevant team hear your needs, anyone's
suggestion could have a chance to be adopted by Microsoft, your understanding will be highly appreciated.
Reference:
download folder – OneDrive UserVoice
Best Regards,
Arck