It might be worth checking if sustain is set to HOLD. In the page where you set set attack, sustain, release, if there is a note graphic displayed, the trig only plays for as long as it is held in Live Record mode. If it’s on one of the loop settings, you will see an indication in the waveform page that playback is occurring, but will not hear a sound unless you hold the trig.
In Step Record mode the trig will play for the note length set on the Trig Parameter page, and I believe the default is a very short note length.
Probably not the issue you are experiencing, but worth checking. If not, this setting is still cool to experiment with. I didn’t know about it until fairly recently.