Thanks for the suggestion, turingtest2, but restoring my iPod did nothing. In fact, it did not restart with factory settings; all my songs and apps and settings were still there even after restore. And so everyone is aware, I backed up my iPod on my computer and restored (NOT updated) it from Recovery Mode as in these Apple directions: If you can't update or restore your iPhone, iPad, or iPod touch - Apple Support. Just to be clear, I'm not mad at you, I'm mad at Apple...again. *sigh* Prepare for a long rant, everyone....
I'm having these same issues (I update playlist in iTunes, connect iPod to computer, Sync, playlist is updated on iPod but also has a duplicate created -- Playlist Name 1 -- that is a copy of the playlist before I made changes in iTunes). That first Sync upon connecting my iPod to my computer is what generates the duplicate and puts the duplicate into iTunes on my computer too. Deleting the duplicate in iTunes doesn't work because as soon as you Sync again, it comes back. Deleting the duplicate on the iPod and then Syncing also does nothing.
The ONLY workaround I've found (if you can even call it that) is to export your updated playlist from iTunes, delete the playlist from the iPod AND iTunes, Sync so that your iPod recognizes that the playlist is gone from your library, import your exported copy of the playlist BACK into iTunes, and then Sync again so that your iPod recognizes it as a "new" playlist. Note, if you have a separate Smart Playlist with rules that are dependent on the playlist you deleted and re-imported, the Smart Playlist will break. I have dozens of interdependent Smart Playlists that reference static playlists in my library. That's why this isn't even really a workaround. 😠
Considering that Syncing each time takes 5-6 minutes for me, and with this method you would need to Sync at least three times, this is an utterly time-consuming, ridiculous process. Take into account that I have lots of playlists that I'm constantly updating and...no. Just no. Prior to Sync breaking, Syncing my iPod by connecting it to my computer used to take 30-50 seconds. And no duplicates would be made; the update would always be iTunes-priority, so whatever version of the playlist was on my iPod would be overwritten by any changes in iTunes. As it should be.
I've searched this forum and it appears this is an ongoing problem with Sync that has not been fixed even after various iOS and iTunes version updates. The duplicate playlists have only started for me this past week, and I don't recall ever making a new playlist on my iPod touch independent of iTunes (except accidentally making On The Go Playlists). However, the other threads are making it sound like this is what caused the problem in the first place.
The other threads I'm referencing are here:
None of these other threads have been resolved. Come on, Apple. I am at my wits' end. I update my playlists constantly in iTunes. CONSTANTLY. Whatever Apple broke, they need to fix it pronto. This is utterly ridiculous.
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iPod touch 5th generation, iOS 9.2.1, iTunes 12.3.2.35, Windows 7 Home Premium