Layouts with Elementor: Missing “Convert to container” button

I have activated the flexbox container function in the newest Elementor version and i started to convert my existing pages, products, layouts etc. from sections to containers. Elementor has a feature to convert a section to a container with a button (see screenshot).

The button shows on pages, product descriptions and html blocks but is missing on layouts. I have tested this on a installation of Woodmart 7.4 without any additional plugins. I don’t know if this problem already existed on Woodmart 7.3.