Slides create weird error

[Wendenburg]

hi there,

using Gatsby 5.13.3 in a big typescript project just to render pages from json sources (Gatsby is not migrated to ts). Creating pages is working. Now I try to create a very simple static slide in createPages:

    createSlice({
        id: `footer`,
        component: require.resolve(
            `.../DummyFooter.tsx`
        ),
    });

The footer is created in [project]/public/slice-data/footer.json

However, no matter if build or dev, I am always running into an error from [project]/.cache/slice/inline-slice.js:
'Slice "undefined for "footer" slot not found'.

Looks like the sliceMapContext is empty.
Did anybody run into something like this?