Is there any problem regarding sync process at the moment?
I’ve upgraded from Anki 2.1.47 to 2.1.48 (Re-install), and am trying to sync media files from Anki Web, but sync is not completed perfectly. Only some part of media files is being transferred very slowly.
This sounds like temporary network issues, as the servers are running normally at the moment. If you have access to a different wifi network or your phone uses a different provider, perhaps you’ll have more luck?