I have an issue with iTunes messing up my iPhone music playlists. I have iTunes and my iPhone 6s with iOS 10.3.3 set to manually manage music. I've noticed that if I ever make any changes to playlists on the iPhone, once the phone is connected to my Mac, running the latest version of iTunes, those changes are gone. I thought I had learned to live with the issue by simply never making playlist changes on the iPhone and only when connected to my Mac. However, last time I did this, several of my playlists were randomly changed, songs deleted from the playlists (not the phone), etc. This had never happened before. Luckily, I was able to figure out what songs were changed because, for some unknown reason, the tracks that were changed all had updated "Date Modified" dates. It took some time, but I got it all sorted out to the way it was. I also notice that, sometimes, when I try to add music, the song is grayed out and never gets completely copied. I have to disconnect the phone and restart iTunes (sometimes a few times) before it will "stick." Now I'm scared to connect my phone again even though I'd like to add some new songs (CD rips, etc., stuff not downloaded from iTunes) as it's incredibly annoying to have to fix my playlists every time, especially when random changes are made automatically that are hard to track. Does anyone know why this keeps happening and/or can offer any help?