You cannot use both add-ons at the same time. If your integration is configured to use the core add-on, then you’ll need to switch. If it’s configured for Z-Wave JS UI, then you should uninstall the core add-on.
https://www.home-assistant.io/integrations/zwave_js/#can-i-switch-between-the-official-z-wave-js-add-on-and-the-z-wave-js-ui-add-on
Can I switch between the official Z-Wave JS add-on and the Z-Wave JS UI add-on?
You can, but you cannot run them both at the same time. Only one of them can be active at the same time.
Follow the instructions in the link above to switch, or follow:
Version 1.0.0 of the Z-Wave JS core app (add-on) includes Z-Wave JS UI, so there is no longer any reason to switch apps (add-ons). Z-Wave JS official add-on to the Z-Wave JS UI HA Community add-on , without losing any downtime caused by the re-interviewing of nodes.
In this guide, Z-Wave JS UI will henceforth be abbreviated as ZUI.