Thanks for reaching out about this in the Community!
Sorry to hear that local files are not syncing to your phone.
Try the following:
Perform a clean reinstall of Spotify on your Desktop, following the steps from this guide exactly.
Try changing the default local files folder on your PC to another one and reupload the files
Create a mobile hotspot from your phone and connect both the PC and your phone to that network. Make sure you have both apps open and reupload the files. This works for some users, as some routers don't support or block networking protocols necessary for the successful upload of local files.
Hope this helps. Don't hesitate to reach out again if you have questions!
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