Google Core updates can have a greater effect on Google Discover than on search. The reason is simple.
Google Core updates not only affect search, but also Google Discover. In some cases, the effect on Google Discover is even greater than on the search. So it can happen that a website that previously received a lot of visitors via Google Discover comes up completely empty after a core update.
John Mueller explained the reason for this phenomenon in the February 19 Google Search Central SEO Office Hours. Accordingly, Google core updates are not about identifying problems on websites or rating them as bad. Rather, core updates should help to better recognize the relevance of websites. The relevance is linked to many different factors.
The information from the core updates is used not only in search but also in Discover. For this reason, it can happen that a change that is hardly noticeable in the search is more strongly reflected in Discover, because Google is even more critical with regard to Discover. Müller had already explained this before.
When asked what can be done after losses as a result of a core update to compensate for losses suffered, Müller referred to a blog post that Google had published on the subject. The aim must be to improve the website as a whole. It’s about many small things that have an impact in their entirety.