This is very similar an already resolved bug:
I’m not sure if the bugfix for that is also squashing the scenario below, so here it is:
- Power on the S2400
- Goto bank E
- Go into multimode pitch
- Open step program mode
- Set Quantize setting to ‘fine’ inside sequencer
- Press E1
- Press E2
Now the machine is frozen and power down is the only solution.