can’t get php fixer to work with custom rules in phpstorm

I want to use php-cs-fixer with a custom ruleset, so I have created a .php-cs-fixer.php in the document root.

In the settings>php>quality tools>php cs fixer I have set the option ruleset to custom and added the path to .php-cs-fixer.php. On save I get no errors, so it is reading the file correctly (or so I assume) but there is no highlighting when the rules are not met. (The others options beside custom do work such as psr-12)

When I run the php-cs-fixer fix app in the terminal it will read the .php-cs-fixer.php and adjust files correctly.

How do I get the highlighting correctly in phpstorm?