Hi there @djryangallagher
Check the Chord Memory Device ( CMD ) and ARP settings, by default this preset has CMD turned off and doesn't use any CMD preset ( pic 01 ), then for the sound that keeps playing after your Midi region, check that "Hold" is disabled in the ARP settings ( pic 02 ). You'll find more about the CMD & ARP settings in the manual as well.
Other than this and if using the preset as default, it could depends on how you're triggering Midi to ANA 2 ( use of Midi device like scale, sequencer sending Midi to ANA 2 ?? ).