After you play a sequencer then you have to reload the User MIDI settings.

Press the SD button to LOAD.
Go to page 2, here you must set everything OFF and then set User MIDI Settings to YES. This loads the .md file you saved earlier from your SD card.
Next:
Go to Program Menus > MIDI > MIDI Presets.
Go to Page 3. Here you can select one of the 3 MIDI presets, including the split point. Choose the one you saved earlier.