Strange behavior with a HAOZEE Z Wave Plus Water Sensor

I have a VeraPlus running firmware 1.7.4453. Everything on it is Zwave

Last weekend I put a water sensor in the network with a probe to the drain next to the water heater (the water heater it 25 years old and I’m expecting any day now it’s going to start leaking)

The device setup as a Flood Sensor and labeled itself a Neo Coolcam (ok yeah whatever)

For several days it was fine - then Monday night 630pm I get a notification from Vera Plus that the device is offline. I tried rebooting the Vera yesterday, it didn’t help. Then Thursday, 944pm I get a notification from Vera that the sensor is back online and it’s been online ever since.

Does anyone have any suggestions as to what might have caused this? The house is empty, it’s a remote vacation house.