Inventory syncing to QuickBooks as zero quantity and/or scheduler receives error regarding permissions for inventory sites.
Webgility is set for multiple inventory sites but QuickBooks is not.
1. In Webgility, navigate to Orders > Settings > Products > Settings.
2. Disable Track inventory in multiple location.
3. Navigate to Products > Settings > Sync Settings.
4. Disable Set product quantity to 0 at time of downloading product, if product quantity not available in default inventory site. Then, click Save & Close.