My hardware drifts or plays at double speedUpdated 6 days ago

Double tempo, or a "MIDI buffer full" message, means the instrument is receiving two clocks. Turn off the DAW's sync output for that port, and leave omniCLOCK as the only clock.

If it slowly drifts, the hardware is often sending clock back as well. Turn off the hardware's own clock output. A very high CPU load can cause the same drift.

If the start is late or garbled, a negative Shift is being used without a count-in. Give the song 1 to 4 bars of preroll and start playback at the beginning of a bar.

Set the shuffle profile to Accurate while you test. That shows whether the groove setting is what you are hearing.

The steps are also in the omniCLOCK manual.