Notes interfering

Hello! I’ve got a problem in cubase 8 that unfortunately has caused several ideas to vanish… Its an issue when draggin notes from one place to another. As you can see, when notes are being dragged(mostly fast) it interferes with the previous note. How can I disable this?

https://www.facebook.com/ShadixDJ/videos/o.122940794511697/10211959004993426/?type=2&theater&notif_t=video_processed&notif_id=1485359930786244