OK, here's the deal:
With the latest update to both iOS on my iPhone and to iTunes, I can no longer sync new songs I add to my playlists to my iPhone. My old songs are still there, but, when I try to add a new song to a playlist, it doesn't appear on my device. However, when I look at my device on iTunes, it shows up as on my device. The new songs just don't show up in the Music app on my actual device.
So, for example, if I add a song, for the sake of argument here, called "X" to a playlist via iTunes, then sync my phone, the song DOES appear on my "all songs" list on my phone but it doesn't appear in the palylist I added it to on my phone. However, if I go into iTunes, click on my iPhone there, and then,, go to my playlists under my iPhone in iTunes, song "X" does show up there. So, the song is appearing on my computer in iTunes. In other words, iTunes is showing it like it IS, in fact, on my device, but, when I go to my physical device and check the playlist on it, song "X" doesn't appear!
Could someone please help me fix this?!?!?!?! I've tried everything I know how to try!!! I've tried un-syncing and re-syncying my songs which worked at first, but, then, when I tried adding a new song to a playlist after that, it didn't work again and was doing the same thing! I've tried other things, too, but it's too hard to explain here.
Please help me! I am not a very skilled technical person, but please try to guide me in laymen's terms step-by-step as to how to fix this!