Zwave measure power does not work on some devices


Some of my Zwave devices suddenly do not report the power consumption(W) anymore. I encounter the issue with some (not all!) of my Neo Wall plugs ánd my Fibaro Double Switches. Oddly enough, the power meter (KwH) and the Voltage (V) do give actual (and correct, up to date) readings. I did not (yet) did an unsecure include of any of my zwave devices, because I prefer to have them secured. I did do a PTP though. Anyone any ideas what may cause this issue and how to solve it?

Thanks for your thoughts!