Hello,
Please provide URL of product with tabs and temporary wp-admin access, so we can take a closer look at your settings.
Make sure that the tabs element is added in content by Single Product Builder.
Create an account via Dashboard (Users > Add new) with administrator role http://prntscr.com/s3rc9m > provide us with username and password via the Private Content area http://prntscr.com/s5mao7 You can use any email for it.
Regards