https://youtu.be/SLUIm5g-GWI
 
Any ideas why this is?
 
Thanks,

Geoff

I can't see any noise coming from Percussion strip alone using Voxengo Span with the scale set all the way down to -135dB.
 
I would start by putting a dedicated spectrum analyzer directly on the output of the track (i.e. last in the FX bin with Prochannel not set to Post). If you still see the noise, turn off everything after the Percussion Strip, and see if it goes away; there may be some interaction between plugins. If that doesn't get it, try moving Percussion Strip from the FX chain in Prochannel to the FX bin.

It only seems to happen after I play a song through a few times.
 
Also, I'm not worked up about it. It just looks like a bug.