As a reminder, back in 2016, Google updated its guidelines for using schema markup on your site with third-party reviews. Google reminded us in 2018 that this is not in accordance with their rich results guidelines. And now, John Mueller of Google reminded us again - he said "You can't mark up 3rd party reviews with structured data."...
-
Reminder: Don't Markup 3rd Party Reviews With Structured Data
seroundtable.com