Years ago I signed a bunch of songs with an online music library.
One way of presenting the music they represent is by making compilation albums with songs of multiple artists. That's why you may see my name appearing on all these different genre-specific collections on places like Spotify, Apple Music, and the like. The video below show what's this looks like on Spotify, for instance.
So any tracks of mine you find on the internet that don't appear on an album or single that I put out, that's how they got there!
Here's an example of my top-played tracks apparently on Spotify.