Confirm PageSpeed Insights & Structured Data Testing Tool IP Addresses with Test Page
PageSpeed Insights and the Structured Data Testing Tool use different IP addresses than Googlebot. There isn’t a list of IP addresses that they currently use, so check this using a test page and analyse the requests coming from these tools.
If Testing Tools Are Picking Up Structured Data Google Should be Able to As Well
There is No Way of Giving Prioritisation to Structured Markup Types on a Page
Some rich results can combine two structured markup types in the search results, however, some can clash so Google will only pick one to show. There is no way of giving prioritisation to different markup types, rather Google’s algorithms will determine the best one to display.
Invalid Structured Data Will Not Affect the Ranking of a Page
Having invalid structured data on a page will not affect the ranking, however, it may prevent the page from appearing as a rich result and impact how visible it is in search. This may, in turn, affect how users interact with the search result listing.
Use Testing Tools To Ensure All Hacked Content is Removed From Your Site
If your site has been hacked and left with virtual pages which are indexed in Google, John recommends using testing tools such as GSC’s URL Inspection tool to understand how Googlebot is crawling these, before performing the necessary steps to remove them from the index.
Google No Longer Support the Webpage Review Structured Markup
Webpage review markup will no longer be shown in Google search results, as reviewing a whole page doesn’t make a lot of sense to them, instead they expect reviews to be for a specific product.
Changes to Review Rich Snippets Limit Available Review Types
The changes made to Review Rich Snippets means Google have limited the support to a certain set of markup types, as well as amending the approach to reviewing your own entity.
You Only Need to Add Author Structured Markup to a Page Once
John would not recommend adding itemprop author schema markup in two different places on a single page as it is difficult to maintain and harder for Google to understand.
Providing a Summary in How-to Structured Markup Is Acceptable
When implementing how-to structured markup, providing a summary explanation of the step should be fine, as far as John is aware.