Can’t see files on an USB stick attached to a Raspberry PI 2

I have formated an USB stick from my Raspberry in VFAT and use it with Syncthing which works fine (dropping files from Windows 10, store them on the stick and access them on an Android Tablet). But when on my RPI and trying to store files from it to the USB stick, I don’t see any file or directory. Just prints System Volume Information. What have I done wrong?