It seems that some search patterns makes the database consistently err. For instance, try to search for "abc- def" without quotes (https://electowiki.org/w/index.php?search=abc-+def&title=Special%3ASearch&go=Go). This produces an exception of type "Wikimedia\Rdbms\DBQueryError". I'm not sure where to submit this bug report, so here it goes :-) [[User:Kristomun|Kristomun]] ([[User talk:Kristomun|talk]]) 19:00, 24 November 2021 (UTC)
The URL provided in the report demonstrates the bug for me as well, showing an error page with the following error message:
A database query error has occurred. This may indicate a bug in the software.
[78afeb232e73667532ef18bc] 2021-11-25 08:44:18: Fatal exception of type "Wikimedia\Rdbms\DBQueryError"