I've tried looking for answers for a couple of hours on this forum and all over online, but I can't find any solutions and I'm getting frustrated.

Basically, it seems to be a pretty common issue but I can't find a fix.  When I make a playlist on my desktop with songs from Spotify mixed with local files, the Spotify songs will appear on my phone but the local files appear greyed-out and unplayable on my mobile.

The root issue seems to be that desktop client isn't recognizing my mobile under 'Devices' even when they're both logged into the same account.  I have even tried changing network settings to no avail.  If I was able to have the client recognize my iPhone and then sync, I believe the local files would show up the phone.

If anyone has any ideas that have worked for them, please share.  I am currently under my free-trial period and will cancel before the 30 days unless I can get a fix for this.