When the dance mix song plays, are you giving this track a thumbs down 👎?
Also, are you able to determine which station this specific track plays on?
Something to keep in mind, holiday stations based on artists may feature non-holiday music from the seed artist and others. If you prefer to keep these stations playing only holiday music, just thumb down any non-holiday tracks.
If you're hearing tons of non-holiday music, I would recommend checking the seeds you used to create your station as you may have added a non-holiday seed accidentally.