Erotome over at LSF reported the following problem:
"While implementing BGM tracks in Novelty, I've encountered an issue where a track set to crossfade into another will spike in volume before fading away, rather than simply fade away at its current volume."
His solution follows: "I did find a workaround, actually, after much hassle. Basically, I had to tweak the Master Volume and BGM volume in the Novel Properties to be very low, and keep the BGM's volume relatively high, and that seemed to negate the spiking volume effect. It's strange, but it worked."
This was posted here with his approval.