Can only use a small amount of storage on my SD Card for Roms

[Dimi]

I just set up my recalbox 2 days ago (still a noob) and I noticed that I can only add up to ~480MB of roms to my recalbox if I am accessing it via my pc/browser/ip.
What do I have to do, to make it possible to use the whole (or more than 480mb) storage space on my SD Card for roms?

Data:

• Windows 10
• Raspberry Pi 3
• SanDisk Ultra 128GB MicroSDXC + SanDisk ADAPTER

Monitoring:
http://i.imgur.com/C60gdkg.png

Tools used for formatting without success so far:

• Windows inbuilt formatting tool
• guiformat
• SD Formatter (the partition always ends up being exfat?!)
• Minitool Partition Wizard
• HP USB Disk Storage Format Tool

I always made sure that the format is fat32 and it is set to primary and/or "Format Size adjustment" is set to "on". I've searched for a solution yesterday for hours and tried nearly everything that I could find, but now I'm close to giving up.

[paradadf]

I didn't get how were you trying to access the SD Card, but I'd recommend you to use read the wiki/manual.
Manual (EN) - Network features

Windows can't read the share partition, where you are suppose to copy your roms.