There is a separate forum for the Jam and you should ask there.
Apparently there is a 2000-file limit for the internal memory and the external card. Beyond 2000 it will stop showing the files. I don’t (and won’t) have a Clip Jam, so there may be other quirks as well.
But all Sansa firmware gets information like Artist from the ID3 tags within the mp3 files. There are some tag formats it doesn’t read, so depending on the ID3 tag format you could have some files that turn up blank.
Sansas can only handle ID3v2.2 and ID3v2.3 . You can change your tag formats in bulk with mp3tag, a free program.
If you don’t have popups blocked, you may see some junkware download buttons all around the real mp3tag program,. The file to download is mp3tagv(version number)setup.exe
When you install it allow itself to be added to context menus.
Under Tools set its Write to ID3v2.3 ISO-8859-1. The ISO is how Windows displays the alphabet, as opposed to UTF on Apples.
Open a problem album with right-click and mp3tag.
Highlight all the files and (under Files) just Save them, which will convert them to ID3v2.3 ISO-8859-1. Takes a few seconds.
Mp3tag will show you what version the existing tags are, if you’re curious.
I like to change the copy of the album on my computer, delete the one on the Sansa and send a copy of the fixed one over, but you can fix the one on the unit if you prefer. The database will refresh when you unplug, which will take a while, but it’s probably worth trying with one album first. If that works, then run all the others through the same process.
Going forward, I’d just run every album through mp3tag upon arrival. I open the album folder in mp3tag. Making sure the tracks are displayed top to bottom in playing order, hit CTRL-A (Select All), and use Tools/Auto-Numbering Wizard with the Leading Zeros option, which numbers tracks 01, 02, 03, etc., and saves them as ID3v2.3 in ISO-8859-1. If the tracks are numbered without leading zeros the Sansa will play tracks, 1, 11, 12, 13 etc. before it plays track 2.