Check the Clock Source (fourth page of the global menu). If this is set to "ext" for external, ensure that the KS is receiving midi clock. Check that the arp on LED is lit. Some sequencers only transmit MIDI clock when they are in play or record mode.
The KS arpeggiator is not running/patches which use the arpeggiator are giving hanging notes.
Check the Clock Source (fourth page of the global menu). If this is set to "ext" for external, ensure that the KS is receiving midi clock. Check that the arp on LED is lit. Some sequencers only transmit MIDI clock when they are in play or record mode.