I just want to chime and and say I have having the same issues with two of mine and another issue with another SmartThings Water Leak Sensor.
Two weeks ago I bought one SmartThings Water Leak Sensor (from Best Buy)and when i paired it, the device handler showed “unknown”, so I set it from the IDE as the same device handler as the three SmartThings Water Leak Sensor I already have. The issue with this one is it doesn’t have a checkinterval so the battery status never gets updated, but it changes from wet/dry as it should.
Now the other two that I bought last week (from Amazon) showed up as “unknown” as well, when I set the device type in the IDE, it doesn’t update the wet/dry as it should staying dry.
I opened a support ticket (I can’t find the ticket number) last Monday, and the support representative said that she turned it over to engineering as it is an issue with ZigBee devices. I haven’t tried any new devices since then, but every attempt to pair the two newest SmartThings Water Leak Sensor results in the same “unknown” and when changed in the IDE never sends the wet/dry signal.
I was wondering if @Tyler or @slagle could look into this as its been almost two weeks and no result yet.