There are a few things you can try to solve this issue:
Firstly, if you are on desktop, we'd always encourage you to use Google Chrome
If you are using our website, try refreshing the page a few times
You should also clear your cache and browsing history
Both for the apps and website, try disconnecting and reconnecting your audio source. Here is how.
Please remember that you'll need Spotify Premium to sync via the Studio.
Finally, it could be that the release is missing
If you are the artist of the song, you can add it yourself. Here is how.
If you are not the artist, please report the issue to the Slack Community in the channel called "catalogue-issues", being sure to follow this guide.