Question Some of the music (within sub-folders) on my USB flash drive does not show up in my car anymore. They used to. What can I do? (More details below)

Jul 6, 2019
I drive a 2015 KIA Forte, with the factory audio system. I'm using a 128 GB Kingston DataTraveler G4 flash drive 3.0 (in properties it says "FAT32"). The flash drive has only music, audio files: .mp3 file type. In the flash drive, most of my music is divided in the following way: Genres (folders) -> Bands (folders) -> songs

In the cases where I use sub-folders within sub-folders, it is set up this way: Genres (folders)-> Bands (folders) -> Albums (folders) -> songs in each of the album folders

It used to work fine since I first bought the car a few years ago. The problem arose last weekend after I added more music to the flash drive, and then connected it to my car, only to discover this problem. "Band" folders that contain "Album" folders have not been showing up. The other "Band" folders, that don't have the "Album" folders, do show up.

Side note: When connected to my computer (Windows 10), everything shows up. Last time I added music to this was about a month ago with the same computer and same OS and it worked fine.

I checked the car manual if there was a limit on the bit rate, and it said 320 kbps. No issue there. I also checked to make sure none of the files or folders were selected to be "hidden." No problem there. I don't understand what could have happened this time around when I placed more songs on this flash drive. Can anyone help me fix this so those folders can start appearing again? I appreciate any help I can get, thank you!
Is not uncommon for head units to have limitations as far as file size, folders size etc. If KIA is nice, they would spell out those things for u in the manual, but sometimes they just stay quiet.

I always recommend folks to load up your smartphones with all the music u want, then BT it to your head unit. It always works, with ANY car.