Cubase 9 VST Performance - Inexplicably different levels in two virtually identical saves

Hello folks

Windows 10
Cubase 9
EW Hollywood Orchestra OPUS
12700k, 128GB RAM, 980 PRO drives.

Having reinstalled Cubase on my new PC. I’ve loaded in an ongoing project, and I’ve been trying to improve VST performance.
EW recently patched OPUS to version 1.2.0 and that improved things…
I saved it yesterday and on the VST performance meter I was noticing the Average Load was around 25% and Real-Time Peak was flickering around 8% - very happy with that!
I loaded my project a little while ago today and noticed the same levels - Great!
I worked on the project very little - changed the pitches of about 6 notes. I was mainly looking stuff up online. When I returned to my project I noticed that the Real-Time Peak level had increased to around 30%. I thought Oh that’s probably because I’ve been online and stuff, or some new scheduled process has started in the background.
I saved my project and restarted my PC. When Windows restarted I immediately loaded in the latest save but again the realtime level was around 30%.
I loaded the earlier save (wherein my project was in exactly the same state minus those 6 note changes) and the realtime level was back to 8%!
What’s going on here?
Virtually nothing had changed in my project between these two saves, and yet they show different realtime VST activity.
This is more of an academic curiosity than practical concern!
Any idea what could be happening here?


Once you select a track, the priority of that track is elevated to Real-Time.

Oops! That very concisely explains exactly what is going on here!
Thanks David_W!