ok, so the drive has a partition, and is recognized and loading in the program. It just doesn't display any game.
I guess it's the same with WBFS Manager (which you should never use, it corrupts your drive when you delete a game with that program !)
To convert to FAT32, you can use "wbfs2fat" by looking in my signature. it has a guide in my signature too.
But before converting it, maybe we should check if the drive is good, if you don't find any game it could be a WBFS header issue. I guess it could be fixed.
I find it strange that the USBLoader is seeing the games, but not the programs.
if you want to test your drive, you'll need this tool :
https://wit.wiimm.de/download.html
but you'll need to read and learn how it works. you can do a lot without touching the drive (there's a test, read only, mode)
this tool can be dangerous if misused (you can format or delete hdd content)
There's another thing you can try, using a manager GUI using wwt as source.
I'll search for that GUI.
edit:
maybe this one :
https://gbatemp.net/threads/wiijmanager-multiplataform-windows-os-x.214002/
or this one :
https://sourceforge.net/projects/wiibafu/ <- I think this one is the most recommended after "Wii Backup Manager" and is multiplateform.