Live mode; Hold and Relatch - not working as expected

There are a few posts for questions close to this one, but none exactly, and none that answers my issue.

I understand that to use the Hold or Relatch function the sequencer needs to be running.

My issue: I can build a chord (any number of notes) in Hold mode… the keys light up… but the “chord” (all the lit notes) only plays when I press STOP and then PLAY. Kind of counter-intuitive (or I am doing something wrong), because as the manual says "Hold allows you to sustain notes played with the keypad,
smartpads, or an external MIDI device. Held notes are highlighted on the keypad. TIP Hold is very useful when designing drones/synth pads or experimenting with an effect like the arpeggiator." … so you would assume that you can “build” chords, to be played as chords, or to use with arpeggiator, as the sequencer plays.