Hello Götz,
It is clear, thank you. However, I did not encounter this issue when reproducing these steps on one of our datasets. Laserscan and images aligned into one component even if one or more components were present in the project.
Did you make sure that all your inputs are enabled for alignment? Can you please send a screenshot of your Alignment settings?
Also, would it be possible to share the dataset, project file, project folder and exact reprosteps with us so we can reproduce the problem?