Is the reason specifically because it includes real tracks.... and if so, how would they know? Or is it because the song sounds similar to something else that a commercial release or to the other songs you are submitting for monetization.

I've had music used commercially and received royalty checks for it. The music used included or was 100% real tracks and this topic NEVER came up.

Real tracks are so good that the ones I have in some of my music has fooled professional musicians who play "that" instrument. I've had them ask who I hired to play certain parts so I really don't see how Landr can tell. I think there's something else going on.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.