This is FAT file limitation. It’s a pretty common issue. This problem occurs when all 512 root directory entries have been used. This problem can also occur with fewer than 512 files and folders in the root directory. Two options, you can either re-format the DAP as FAT32 in windows. The second option is to start using folders. delete one track and then create a folder and copy half of the files into the folder. Make sure not to have too many files in one folder and you won’t see the issue.
Good Luck
