Plug-ins disappearing from automation?

Hey folks. Brand new issue out of nowhere. I had automated a parameter of Sonitus:reverb for this track, but now it's not showing up as an available plug-in to automate. (The only available option is "PC-Track Eq" aside from Volume, Automated Mute and Pan.) The envelope is still there and grayed out, but it doesn't even pop up as orphaned. Interestingly enough, Sonitus:reverb does show up for automation in some other tracks of the same project. SUPER weird.
 
The only thing I've changed since last working on this project is update Sonar (Professional), the Engineering FX suite and some XLN plug-ins via respective Command Centers.
 
Any thoughts out there??