Hi, I had the same issue with a Fibaro wall plug which left the network without warning. I re-included it with the "Replace failed node" function, but the icons still showed the exclamation mark (see my post at viewtopic.php?f=3419&t=25830 ).
Maybe I just had luck, but I just found in the expert UI under "Device" -> "Status" in the device list a button with a circle on it behind every mains powered device. Above this column is a "Check all" button also with a circle, so I think the button in the device row checks only this device. After clicking the button, it looks like the icons are back.
Can anyone confirm that?
Discussions about Z-Way software and Z-Wave technology in general
Yes, I can confirm that doing this operation (clicking the check connection circle for each single device) recovered two icons on the first attempt. Going over the remaining devices once more reset the icons to their correct state on the remaining devices. Spooky - but i worked...