Simple Drum loop problem

I set up a simple 4 bar, 4/4 drum loop (very similar sounding to Oasis “Supersonic”) and copied and pasted it across. Every time it passes through bar one of the loop the high hats flange, like a doubling sound. The midi maps look good with no anomalies. Latency is around 6ms.

My midi track is triggering my MOXF6, which is connected to my Focusrite (my driver in Cubase).

Any ideas?