This seems to be working for us:

We have Quickbooks (2018 multi-user) hosted on a PC.  The QB file(s) is local (within a documents folder on C) We OneDrive set to backup/sync the entire Documents folder.  I turned OFF the option to have "Files On-Demand" so that the files stay local and also backup to Onedrive.

As a secondary, we perform a daily QB Backup to Google Drive (MyDrive) folder.