Composer can't symlink a local package?

Question

Composer

When you run composer install / update - the package is correctly loaded via a symlink into the vendor folder, phpstorm sees it and calmly navigates to its classes by ctrl. But Laravel throws an error:

include(/var/www/vendor/composer/../package/my-package/src/Laravel/MyPackageServiceProvider.php): failed to open stream: No such file or directory

It falls on autoload, probably a problem at the composer level.
The composer package is stored locally. I included it in coposer.json of the main project like this:

"require": {
    "package/my-package": "dev"
  },
//***
"packagist.org": false,
    "local": {
      "type": "path",
      "url": "../my-package",
      "options" : {
        "symlink": true
      }
    }

As a result, the symlink is created as it should be:

According to the created symlink, everything is correct - all the package files are located there, as they should be.
If I manually transfer the package folder to the same directory (where the composer puts it when install / update) - then everything works.
What could be the problem?