Make sure you follow all of the instructions, completely:
- Z-Wave - Home Assistant
- addon-zwave-js-ui/DOCS.md at 5ff4872985ac2a612ab4568499b448bc047c527b · hassio-addons/addon-zwave-js-ui · GitHub
Also a guide here: Switching Z-Wave JS Addons with Minimal Downtime! Z-Wave JS (Official) to Z-Wave JS UI (Community)