Can you let us know if you've already tried to log out > restart your device > log back in? It's also a good idea to try clearing your cache to remove any old files that might be causing issues.
If you still don't see your liked song, or any of your usual playlists for that matter, it's possible that you've accidentally logged in in a different account. You can check this page out to see the possible ways to log in and what steps you can take to locate the account that has your Liked songs.
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