MacOS CPU usage high even when idle

I’m new to cubase and was setting up a project template with a set of empty Kontakt instances with routing and FX sends with a couple instances of Fabfilter Pro-R. I notice that my system CPU jumped up in usage even though nothing was playing.

Doing some test I narrowed it down to what seems to be using VST Reverbs, even when idle takes about 15% cpu per instance loaded.
My test was basically to create an empty project
Add an Effect Track
Set the plugin to be any of the VST reverbs I have (Fabfilter Pro-R & two Valhalla)
Check the CPU (will be around 60-70% at this point)
Turn off the plugin in each of the tracks
Check the CPU again (will be down to ~10%)
I did this test with both the VST2 & VST3 versions

I’m using a 15’ MacBook Pro 2018 running Mojave and Cubase Pro 10.0.15

I tested using the same plugins in Ableton and also using VE Pro to host the VST and I don’t see the same thing.
Is there something I’m doing wrong. It seems to be related to the VSTs and perhaps something the VST developers have to fix, but given I only see this in Cubase is it doing something different in how it loads the VST compared to other DAWs?

I tried adjusting my buffer size, disabling ASIO Guard, changing ASIO Guard to low & high; nothing seems to help
I like a lot of the features of Cubase but since my only machine is a MacBook I’m more sensitive to CPU impact since those fans can really get working hard quickly once I start actually playing through tracks.