Smoke/CO Listener Not Working Consistently

I just set up the Ring Alarm system and put a Smoke/CO Listener a few inches from a smoke/CO alarm. Put the Listener through testing and worked. After that set off three "test" alarms on the smoke/CO alarm next to the Listener. One time it triggered (saw the lights on the Listener indicating it sensed the alarm), got the message through a phone call, and the Event shows in Event History in the app. The other two times the smoke/CO alarm blared at full volume but the Listener didn't respond. The app shows the Listener "Actively Listening".Any ideas why the inconsistency? Anyone else that's seen this issue?Reset the Listener then go through set-up again? Defective Listener? Put an Extender closer, even though the Listener shows in the app as connected?Thank you for any suggestions.