Review rich snippet isn't appearing anymore

[mattam]

Hi,

We have recently lost the review rich snippet for product that used to consistently show it for a long time. On top of that we have also lost the breadcrumb. The markup hasn't changed on these pages and gwt data tool tester doesn't show any anomalies.

A few weeks back we have deployed a new property that list reviews from the first site without actually being under the same domain. Would that be an issue, review may have been considered as plagiarism somehow? Is there a way for us to confirm this theory?

What are others factors that may have lead us to lose those rich snippet?

Thanks