iTunes issue - need to sync twice to add music, playlists, etc.

Hello lxworld,

Are you syncing wirelessly or via a cable to the device? If you're using a cable, have you already had a chance to try using another one?

Is there any security software installed on the computer that's being used? If so, does temporarily uninstalling it seem to allow the sync process to proceed smoothly?

This page can also provide some help for the syncing process: Sync iTunes content on PC with your devices - Apple Support

As an example, if you’re syncing your music using "Selected playlists, artists, albums, and genres” categories, make sure each category you want included on your device has been checked, especially the ones that are already on your device.

If you miss selecting something that’s already on your iPhone, iTunes interprets this as you want to have it removed.

Cheers.

Hey there lxworld.

Please do review the steps that were previous suggested to you. If you continue to experience issues, reach back out to us and let us know. We'll do our best to continue helping you out or point you in the right direction for help. If a different issue arises in the future, you can always create a new post and we'll help you then.

Thank you for using Apple Support Communities. Best of luck.