We have released an updated ZWave device binary this evening.
Today we discovered a bug in the ZWave device. A very old bug that's been there for a long time. This bug caused commands sent to multiple sleeping devices to be dispatched when a sleeping device woke up, even if the messages weren't meant for it. Those extraneous messages would time out, obviously, and get lost, so their intended target never received them. If three of these timeouts happened in a row then the ZWave DCE device would think that the USB dongle had a problem, so it would soft-reset it. This would cause all pending undelivered messages to get lost.
As usual pleased run the updater script to download and install this update on your System.
All the best