VST instrument distortion?

I have a A&H Qu-Pac connected via USB to my PC which I use it as my main audio interface.

When I load up a VST instrument in Cubase and change preset while holding a key I sometimes get all the audio out of Cubase distorted. The distortion sounds like a bit rate reduction.The distortion will affect all audio tracks until I switch the preset again a couple of times where it will return to normal. I can switch back and forth and get the distorted preset to sound normal by doing this.

It only happens on VST instruments which don’t mute as it changes presets. ImageLine Harmor is the one it happens on the most.

I have updated Windows 10 , updated all the drivers, disabled unused USB devices, disabled onboard audio, disabled USB auto power down, set the background services correctly etc.

I’ll see if I can record the audio and post later.


The drums are a stereo audio track. You can hear them distort when I change the preset.
The VST is Harmor , it also does this on other VST instruments which don’t mute during preset change.

edit: fixed broken link.

Just completed a fresh windows installation, still doing it.