zWave weird behaviour, ghost node

Unsuccessfully joined zWave device:

Then I disconnected it from power and trying to remove it (hit the remove button):

Why it still shows live log entries, as should not have any at all as removed from power source?? Then impossible to remove and stays as ghost node...

If that can help in identifying the route cause - just power cycled the hub and the ghost node magically disappeared.
Still, the question above remains.