Enabling the new OneDrive Sync Client for Office 365 SharePoint:
While syncing my library’s to another computer I found it was opening Onedrive for business instead of Onedrive app.
I had this on my main pc aswell, however I logged in to it on another account and I could setup the sync.
Today I have found that a setting needs to be changed in the tenancy.
Login to the admin portal > under admin centers select Sharepoint > Settings > Sync client for sharepoint change to start the new client