ZWave: system migrated: on/off sensors now very slow

[frankb (Frank)]

@AndrewFG

There is one node in the stick that does not correspond to a physical device; and I don’t know how to remove it.

Most likely this is the clue! I’ve had similar problems (with OH2). Removing dead nodes helped a lot.
Look here for instructions on how to do that with Aeotec Stick: Remove a ghost Z-Wave Node from HABmin - #8 by devTechi