How do I sync voice memos to iTunes successfully on iPhone?

I have a bunch of voice memos I wanted to create an iTunes playlist with. These are all original recordings I took myself on my iPhone, they do not exist anywhere else on the internet. I downloaded them from iCloud and dragged them into iTunes, for the most part with no problem, and synced the new playlist with my iPhone. Only two of the 167 tracks wouldn't load properly. They appeared in the playlist but they were greyed out. When I clicked on them this message appeared "This item is not synced across your devices". I deleted them from the playlist and readded them and synced again. One of them synced fine, but one of them still gives me the error message despite multiple syncs. There is nothing unique about this track, its the same file type and similar size as all the rest of them. I'm flummoxed as to what to do next.

[Re-Titled by Moderator]

Original Title: Can't add track to iCloud playlist