Kodi - Access sub-folders on USB external drive

[StarrySky]

Hi
I've attached an USB drive to my Android Box that contains all my videos. The drive is formatted with FAT32.
When I add a source in Kodi, I can see the drive under storage/571E-D8E4 (this alpha-numeric reprensents the USB port name I guess). I can now browse the drive but I cannot access to the sub-folders, even though I can see them. When I click on one of them, nothing happens.
So, I added the root folder to a source and selected the Scan recursively option. But Kodi only added the few movies that were in the root, but nothing from the /movies folder.
Is it a limitation from Kodi ? should I put all movies at the root level ? otherwise, what should I do ?

thanks

[october262]

FAT32 has 4GB file size limit, try formatting the USB drive as NTFS
and try again to see if you can access the sub-folders

[lingyi]

OP's main machine is a Mac. Format to exFAT is compatible with both Mac and PC.

[StarrySky]

thanks for your answers, I'll try both.