Problem with disk size

I'm currently running Pardus linux 19.2 XFCE and I have an SSD of 120Gbytes where I have the boot partition and the root partition then I have an HDD with a home partition of around 495Gbytes and a swap partition of around 5Gbytes. My problem is that when browsing my home folder in the file manager I see that I have around 423Gbytes free. The problem is that my home folder weights around 400Mbytes. The strange thing is that in the DISKS application is all ok, I checked it to see if it was something wrong with partitioning but it is all right it shows the 495 Gbyte home partition. Even when I launch timeshift I see that there are around 480Gbytes available. My question is why does the file manager shows around 420Gbytes and how do I fix that? Thank you in advance for the attention you'll give to this message.