Note repeat acting oddly with Tempest

After hooking up the MPC1K (JJOS2XL) to the Tempest I've had some issues with the note repeat function. The notes play in a oddly timed manner no matter whether theyr're 1/8, 1/8-3, etc. The best way to describe this would be that it has a sort of swing to it. Any ideas why this may be happening? I tried both using Tempest as master and slave.

How have you got them connected?

The simplest way to test would be to only connect the MIDI out from one of the devices to the MIDI IN to the other .. e.g. no other gear connected especially no USB to MIDI devices..

If MPC is master logically there should be no change at all..

I had issues where if I had my MIDI clock signal out of the MPC going into either of my Emagic AMT 8 midi racks some of the other devices would go haywire (quadruple time).... I fixed the problem by using the input of a MIDI controller.. --- so do this isolation test.. and see if you get a better result.

If you do, then you need to work backwards to identify which configuration or bit of kit is causing the problems