It should work like that, if I try it on my local server with this:
/#search/q={phrase}
It redirects me perfectly. You may have a script there or a .htaccess mod_rewrite rule that also affects that and converts the URL after redirection. It should work with anything you put in there. Some browsers do treat the anchors differently and prevent redirection when they see one, so that’s why I recommended the “?” or “&” to basically trigger that.