Thank you Alec,
First I am trying to reindex adding this code to the file lib/pkp/classes/search/SubmissionSearchDAO.inc.php in order to skip words with those problematic symbols
EDIT: It worked, the re-indexing was completed.
Regards,
if (PKPString::strlen($keyword) > self::MAX_KEYWORD_LENGTH) return null;
if (preg_match("/[ππ΅πππππ¬ππ πππΏπππ§ππππππ‘ππ―ππτ]/", $keyword)) {
return null;
}```