A Microsoft file hosting and synchronization service.
Hi David,
Based on your description, I would like to confirm whether you installed the next generation of OneDrive for Business sync client.
If so, you need to sign into the client with your Office 365 account in order to sync your OneDrive for Business library:
If not, please try the new sync client.
For more information, you can refer to the following article:
Get started with the new OneDrive sync client in Windows
Thanks,
Qing