VST notes not in sync visually with audio

Example:
I use Melodyne (as an extension) on an event. The notes are visually on time, but when I hit play and the cursor moves, the sound comes, after the start of the note (visually).
Same thing happens in Superior Drummer, the notes are placed on time, but I hear the sound after the note visually start.
There must be something I messed with VST, because it doesn’t happen with events directly placed on the Cubase timeline.
It must be project specific, because, if I load an empty project and use the same vsts, the notes are in sync in audio and visually.

What project specific setting should I search for to fix this? I have a couple of projects with this issue.

Thanks!