Processing a space character in Workflow calculated fields

Am I missing something in the documentation, or is calculated fields unable to process a space character with its text functions? I see nothing about an escape character.

For example, {position(hello hello;e)} returns 2

but {position(hello hello; )} returns Warning: mb_strpos(): Empty delimiter in /var/www/clients/client1/web1/web/scrm/modules/AOW_Actions/FormulaCalculator.php on line 344