I just added my gear configuration to my signature so you can see what I use.
The project in which I am trying to use the MPK is almost empty. No audio. One Superior Drummer midi drum track and the track I am trying to use the MPK with - midi bass through Halion 5. It is 3.5mb in size. All plugins and channel strips are bypassed. ASIO guard is switched off, so it’s latency is zero. Driver latency in is 11.995ms and latecy out is 13.741ms.
Even when I reduce the buffer size of the Focusrite interface down to 32 (the minimum) the latency problem is exactly the same as it is at 512, except distorted.
I have a hunch that the ‘round trip’ required by ther MPK being plugged into the PC and not the interface is the problem, but I don’t have the technical background to know if this is right. I can’t think of any other explanation.