Broken after update 3.0.0

After the update to 3.0.0, the search results make no sense at all.

No matter the search phrase, the result consists of the same five posts and none of those are relevant to the search.

The link shows it all. I know there is a post that has Tamariz in the title, and none of the posts shown in the search result contain that term. Search for “casal das areias” and one gets the same five posts, but not the post with that title.

Confirmed that it is not a problem with the cache. On the local staging server, also updated, same issue is observed.

The page I need help with: [log in to see the link]