Review Snippets Gone Since June 2021

Hello,

So my reviews snippets have disappeared and it seems like this happened in June of this year. This seems in line with an update from Google. As well, upon checking one of my competitors, his review snippets are gone as well.

Are there any new requirements to be able to have review snippets? All of the big companies seem to still have them.

Thanks for the help.

In one of the recent updates, there was a huge drop in the percentage of review snippets shown,
it fell from 50% to around 3%, google did report this as a bug,
take a look at this one: https://www.seroundtable.com/google-drops-review-snippets-from-search-results-31806.html

Are there any required changes that have to be made for the snippets to show up?

Could somebody please shed some light onto this subject? I know that I am not the only one effected by this. Thank you.

My website, and a person who I know - both of our websites no longer have Review Snippets. Why?