Check to see if there are any algorithmic penalties or any potential issues with penguin updates. If you are checking your Google Search Console reports regularly and Google has not indexed your markup, or some aspects of your product's structured data, like an aggregated rating, seem to be missing, you may need to simply give it longer. If in doubt, make sure that you did send the webpage URL to Google to be sure it crawls it again via the Fetch with Google tool. Then continue to audit to know if the structured data is picked up the way intended. For example, both product ItemPage objects and Product/Offer objects showed be recognized in most cases.