This is no longer a beta issue. Quickly goes and stays offline after Refresh. Refresh takes it offline. Was stable for over a year until a week or two ago. @bcopeland @jtp10181
https://community.hubitat.com/t/2-5-2-124-zooz-zen55-goes-offline-during-refresh/166464
Same with mine since 2.5.2. Have been using for several years with @jtp10181 driver. Is there a built in driver? Just checked and could not find one. I still get notified if I test my smoke detector.
And in theory the .133 version in beta should fix it 
Correction... It's not in beta yet.. The next build of .134 will have it..
as he waits with bated breath for .134
.134 has fixed it. Thanks