Midi Bounce g Picking Up Information that Is Not Visible

I am on Cubase 8.5.15 and I have noticed some odd midi bouncing behaviour… I am comping drums from an electronic kit just basically editing fills. When I shorten midi events on the drum track and I bounce the midi, the non visible midi notes are showing up in the bounced event Oddly, when I cut the midi track at the point where I I previously shortened it and then delete the unwanted midi event, and bounce, the notes are still there…

My only work around has been to not bounce. I have checked all lanes in the tracks to be sure that I wasn’t picking up something that I missed in another lane… there was nothing.

Can someone try a midi bounce from say Addictive Drums or something similar and test the bounce? It is likely user error but damn if I can spot what I am doing wrong.