Cubase 10 extreme real time peaks

I don’t currently have, and never really have had massive problems with spikes on any of my systems. Generally crap performance on OSX all round - well of course I’ve grown accustomed to that!

However I have had one particular spike on my system which has driven me nuts for the past six months or so and is totally repeatable!

After a couple of minutes of opening Cubase I get single massive spike which cuts out playback and pins the meters for a couple of seconds. Every single time.

I’ve had all the CPU utilities running to try and see if it was another app causing it, but when it happens there’s nothing else going on but Cubase.

This last week I shut down using the Control Room which I had temporarily been using just for Sonarworks, and lo and behold, that particular spike has now gone…