Summary:Several factors influence when Google may display rich snippets:
Crawl frequency – Google needs to re-crawl your page after rich snippets are added
Website authority – Frequently updated or well-linked sites are crawled more often
Technical setup – The structured data must be valid and conflict-free
Google’s discretion – Even valid rich snippets are not guaranteed to be shown
A few days – For frequently crawled websites
Up to a few weeks – For less active or newer websites
Google decides if and when rich snippets are shown
Seeing structured data as “detected” does not guarantee display
Make sure there are no conflicting rich snippets on the same page