When using the extension with MySQL, some database servers may use the default MySQL MyISAM stopword list (see https://dev.mysql.com/doc/refman/8.0/en/fulltext-stopwords.html). This may lead to unexpected search results (e.g. search for german brief may return zero results), since brief is a default stopword.
It is therefore recommended to either disable the feature if possible by setting
ft_stopword_file = ""