Doubt if it's the case here, but the day we picked up our MH, the CO alarm went off, apparently caused by a seat cushion that was propped up against the alarm. It may have been detecting off-gassing of the foam in the cushion, and reset after we moved the cushion.
Our previous MH's alarm would "chirp" every couple of seconds when the batteries were low.
2019 Thor Freedom Elite 30FE w/2020 Jeep Gladiator Toad
Living The Dream in "God's Waiting Room"