In the past month or so, there has been an uptick in the number of manual actions seen around "Spammy Structured Markup" or rich snippet manual actions.
The reason might not be due directly to intentional spam but rather WordPress plugins that add structured markup data to your web site automatically.
There were probably a dozen or more threads in the past month, here are some of them:
- Pls help received this Incorrect structured data might remove rich snippets
- Manual action, message type [WNC-646200]
- Partial Match - Manual Action
- Review Snippets Suddenly Gone??
- Spammy Structured Markup - We don't find the problem
Again, those are some of the reports but there are plenty more.
Jennifer Slegg narrowed them down to the following WordPress plugins causing the issue:
- WP-Ultimate Recipe
- EasyRecipe Plus
There may be others.
The main issue, structured markup shouldn't be used on every page on your site and many of these plugins just add them to everything.
The penalty may read:
Google has detected structured markup on some of your pages that we believe violates our structured data guidelines. Because incorrect information lowers the quality of search results for users, rich snippets will not appear in Google Search results for pages with incorrect structured data markup. This manual spam action has been applied to pinoyrecipe.net/. We suggest you update the incorrect structured data and file a reconsideration request once you have fixed your site. After we determine that you have complied with our guidelines, we will remove this manual action.