I am playing audio on this board using MKR 1010 Serial1 port. The board was playing files from a SD card but not the correct one. There was an arbitrary offset from the intended file. I had named the files on the SD card (formatted FAT32 on Windows) as "001.mp3", "002.mp3" and so on. After several hours of checking and re-checking code and libraries I couldn't find anything obvious. Finally I went to Command Prompt on Windows and did a "DIR" command on the SD card. Turns out the board was recognizing the files in the same order as shown by the DIR command! The actual name (ex. 001) of the file did not seem to matter. So I deleted all files and copied them back to the SD card in the order of the file name (number) and all is good now.
Anyone else experienced a similar issue?