If you are in the European area after that Google has implemented the 'Europe’s new copyright law' that is already enforced in France, you could experiment the loss of your snippets and indexed contents unless you use a special robots meta tag to opt-in and have your snippet text, videos and images being displayed in SERP as usual.
On September 24 2019, Google announced new snippet settings and changes to the robots directive to provide site owners with options to limit the content included in their search listings. These new settings are part of Google’s response to the first implementation of the European Copyright Directive by France, which was in part aimed at getting Google and other internet giants to pay for use of publishers’ content in its results. Google refused to pay publishers in France and other EU countries, as a result they must opt-in to have their snippets presented in Google results otherwise they will disappear!
Thanks to JSitemap using the robots directive specified below for text, images and videos, you will force Google to fully show snippets for your website:
You can control and opt-in how Google will show snippets for your website using the syntax:
'max-snippet:[number]' you can specify a maximum text-length
'max-video-preview:[number]' you can specify a maximum duration in seconds of an animated video preview
'max-image-preview:[setting]' you can specify a maximum size of image preview using either 'none', 'standard', or 'large'
If you set '-1' to a numeric value Google does not apply any limit and all snippets will be formatted as usual.
More informations about this argument can be found at the following links: https://www.searchenginejournal.com/google-lets-site-owners-customize-their-search-results-snippets