Matter Nuki 4 pro and Amazon Echo 4

Hello,
after the Amazon Echo 4 can now function as a Matter hub, I tried to connect my Nuki 4 Pro via Matter. Unfortunately, in the Nuki App, when setting up Matter, I cannot select the Alexa App. However, after enabling Matter there and then opening the Alexa App, a compatible lock is displayed. In the Alexa App, I completed the setup process, but unfortunately, I receive an error message at the end: “Something went wrong.”
The Nuki App now shows that my lock is connected via Matter, but it is not available in the Alexa App.
Why is this not working?