Nuki V1 Smartlock and No Apple Watch Standalone Opening function

Hi,

I have a Nuki Smartlock V1 and I tried to use my apple watch 4 (without connection to the iPhone) to open my door. There is a connection failure. It only works with my connected smartphone. Latest Software/Firmware is installed.
Am I missing something?
Regarding: https://nuki.io/de/blog/nuki-news-de/apple-watch-update-jetzt-auch-ohne-iphone/

I have the same setup and it works without problems.

The Smart Lock can handle only one BLE connection at a time. Make sure that there is no other App open, while you try to connect with the watch.

If you haven’t done so, try to reboot the watch.