Digitakt / Acidlab Miami / XoXboX

I’m using the Digitakt as the brain of a little setup using Midi Clock to run the internal sequencers of a Miami 808 and a XoXbOx 303.

When I press play, the other sequencers often start perfectly in time, or they could start very slightly late, just fractionally enough for me to to notice that they missed the starting gun. Sounds feel like they are dragging, snares are slightly late for example. Press stop / start and then they Sync. There is no drift, the clock timing is solid…

I have the Digitakt midi out going to a new Kenton Thru box (mains powered), with short Midi cables connecting everything.

What could I do to stop this happening?