If you update the device handler for an active switch, do you have to go back and redo any settings you may have changed? (dimming speed, led off etc) This would be using smartthings.
Only if the device handler update was made to fix a problem with the way it handles the configuration options… But rarely would you have to re-do any settings… Especially since these are actually stored on the device itself…
After a device handler update, configuration settings should still be set on the device, though if the updated DH adds any new features or changes the behavior of how some function works, you may need to just go into the ST device, edit the settings, maybe not even have to adjust anything, then save.
I had this issue recently with a DH update to my Zen27 switch. It would only trigger with the physical paddle and not through z-wave commands until I went into the settings page and saved it. Before that point, ST would correctly reflect the state of the switch, but was unable to turn on/off the device.