MP3 Files' Length Not Appearing in Windows Explorer

[br4]

I have a new SanDisk 64GB Ultra microSDSC SD class 10 TF card; formatted FAT32.

I have about 400 MP3 files I want to copy from my hard drive (NTFS) to the card (FAT32), to be used in an MP3 player. I've done the copying in a few different ways (Syncback, batch file using xcopy, QDIR, Windows Explorer) and after I copy a group of files, sometimes some of the files on the card do not show the length values, so I recopy them. Usually this works.

When the first set appears OK, I then go to the next set, and so on.

For some reason, a file that appeared OK, after other files have been copied, will not show the length field.

All of these files show the length in Windows Explorer for the hard drive, but for some reason this gets lost in the copied version, even though the copied version shows the name, type, date, and size.

I sent a note to SanDisk asking about this but, so far, no response.

Anyone have any idea what's causing this and how to correct?

Thanks for any info.

 

[fireberd]

I'm close by, Inverness.

I just tried two MP3 files. Copied them to a USB 2.0 flash drive. The two MP3 files display the file size.

I'm on the Win 10 Creators Upgrade version, not Win 7, may make a difference. I don't have a Win7 system to test.