On September 1st, Google started limiting the number of unique search terms it will show in the Search Terms report and will show only the ones that have been searched by “a significant number of users.” It is unclear so far what the word “significant” means in terms of the actual number of users or searches, but official documentation indicates that searches with clicks will be removed from the report. API reporting is impacted too, so it’s not limited only to the Google Ads UI reports.
It means that there will be some completely irrelevant searches you’ll be paying for, but won’t be able to exclude, since there won’t be any direct way to identify them.