2018 Civic cycles through partial list of audio files only

[dlm]

I put files on a thumbdrive into two folders. Each folder has ~ 600 MP3s. I noticed the player plays only a partial list of MP3, over and over, when random folder shuffle option is selected. The random sequence seems to actually not change!!

I re-organized the files into folders with each having ~ a hundred files. I noticed a better shuffle. If I play the files with no shuffle, player simply goes down the list.

Question: any documented limit on the number of files in a folder that the player can shuffle? Rather strange.