Keen vent battery drained. zigbeeNodeType: NON_SLEEPY_END_DEVICE

I have one of several Keen Smart Vents that drains the batteries in just a few weeks. The other vents have not had this issue. The event history on the problem vent shows events being registered one to two times per minute compared to once every 5 minutes on the healthy vents. I noticed that the ide shows a zigbeeNodeType: NON_SLEEPY_END_DEVICE while the healthy vents show it as SLEEPY_END_DEVICE. Any ideas how to get the problem vent to become a zigbeeNodeType: SLEEPY_END_DEVICE ?