I’ve had this issue for a while now, I was hoping that updated Firmwares may improve things. But alas it hasn’t (inc Beta 7.30 1.7.4783).
The issue first was shown with a Z-Wave remote constantly going thru batteries as it was acting as a repeater (for some reason) but then when it was no longer functioning, the Z-Wave on/off switch wouldn’t communicate with any device or controller, which was at a maximum of 5m away.
To include the Switch (Aeotec Smart Switch 6) it would need to be within 2 meters of the controller. 3 meters away, it wouldn’t pair or be discoverable.
Added to this it appears the beta has stopped scenes from running on schedules.