Problem with php-cs-fixer: all files not readable with incorrect slash in wsl2 unbuntu?

Hello,

I have php-cs-fixer setup and it was working but it has stopped recently. I am assuming I have changed a setting somehow and I have no idea what it is. I am wonerding if someone may be able to point me at the right place.

This running phpStorm on windows with docker running in wsl2 ubuntu, everything is fully updated.

When the inspection now runs, I always get this error:

The path "path\to\file.php" is not readable.

As far as I have been able to figure out, it appears that it is just the slashes are the wrong ones. It appears to be using windows \ instead of unix /, so the read fails.

Does anyone know where to configure the slash php-cs-fixer uses? Or whatever other thing is wrong?

Thank you,

Jeff