May we know the storage temperature of the affected product? From the photo, Our QA has noted that the drum has water marks and the sticker is wet. If these were stored at cold temperature, separation is a normal phenomenon. According to the report you sent to us, brix and pH are normal, does this mean also that flavor is normal (no fermentation)? Did you note any abnormal condition in packaging (bloating)?
As per our QA, if there is no problem with flavor, product separation may occur if product is stored for longer period as the product is thick and have not undergone homogenization. The product will still be okay and will go back to normal state when mixed.