SQL-DATABASE ERROR

Database error in WoltLab Burning Board (2.3.6): Invalid SQL: SELECT * FROM bb1_info_charaktere WHERE (synchronsprecher = 'Ulrike St��rzbecher' OR (synchronsprecher LIKE '%Ulrike St��rzbecher%' AND synchronsprecher LIKE '%;%') OR synchronsprecher LIKE 'Ulrike St��rzbecher%[%') AND synchronsprecher != '---' AND synchronsprecher != '-hb-'
mysql error: Illegal mix of collations (latin1_swedish_ci,IMPLICIT) and (utf8mb4_unicode_ci,COERCIBLE) for operation '='
mysql error number: 1267
mysql version: 10.5.19-MariaDB-0+deb11u2-log
php version: 5.6.40
Date: 01.06.2023 @ 18:03
Script: /hoerspiele.php?action=search&syn=Ulrike%20St%EF%BF%BD%EF%BF%BDrzbecher
Referer: