Cubase 8.5.3 problem (Video)

PLEASE LISTEN TO THE TIMING OF THE HI HATS WHEN I CLICK IN AND OUT OF THE BASS CHANNELS MIDI EDITOR.

This has been happening on and off since 7.0. It makes Cubase unreliable and pretty much unusable. It can also happen even if i just click on (highlight) another track. Anyone have any ideas ?

CPU is at roughly 30/40pc
Using ASIO Guard High
VEP Pro as Input.

The computer is fully optimised in both OS and Bios.

This shouldn’t be happening!

https://www.youtube.com/watch?v=devZZP7GLEs&feature=youtu.be