Kobo showing number of chapters/files

Hi,

My name is Sebastian. Recently I did some ebooks for a client. We checked them using either iBook or Adobe Digital Edition. I also used on my own Calibre. Everything was fine until the client came back to me stating that the ebook have a major error. When viewed on Kobo Arc there are numbers appearing in grey every time a chapter starts. Actually, the ebook has two HTML file: the cover and the body.

You will see in that image number two, smaller in grey right on the side of the title: Diabetes and Tobacco.

Why does the client think is an major error I have no idea? Why in fact Arc displays that also puzzles me. Those numbers are never displayed on iBook, Calibre or Adobe Digital Edition. I do not have a tablet to test it but I am sure that it is not something I done.

The ePubs were created in InDesign CC and exported as epub. I am doing this for all my clients. None were using Arc so far. Except this one.

Is there a setting in Arc to show/hide chapter numbers or the numbers of the chapter within an epub?

Warm regards,
Sebastian

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