If your iPod Shuffle is not functioning properly, you may want to perform a soft or hard reset.
You can perform a soft reset on it by powering it down for 10 seconds then powering it back on. Ensure the iPod Shuffle is disconnected from your computer during the soft reset.
If the device is still giving you problems after a soft reset, you may want to hard reset and restore the software using iTunes.
- Plug the Shuffle into your computer.
- Select the icon for the shuffle. It should be listed toward the upper-left corner of the iTunes window.
- Choose “Summary” in the left pane.
- Select “Restore iPod…“.
For more information see Apple’s document on resetting the iPod Shuffle here.