[L 5.6] gitignore in storage folder

Hi,

I have certain files on my storage/app/public folder, everything must be ignored by git except one folder.

I've tried many way in the git ignore and none seems to works except removing the *.

Here is the storage/app/public/.gitignore (upper level .gitignore causes no problem)

*
!.gitignore
!files/

here is my git status --ignored

.idea/
.phpstorm.meta.php
_ide_helper.php
bootstrap/cache/packages.php
bootstrap/cache/services.php
composer.lock
node_modules/
package-lock.json
storage/app/public/csv/
storage/app/public/files/
storage/app/public/tiles/
storage/logs/laravel.log
vendor/

Am i missing something ?