Charts are not showing in HTML view

Charts are not showing in HTML view

Hi,

Maybe I have not used the search function good enough, but I couln't find a topic concerning my issue. 

The problem I'm facing at the moment, using the Zoho Sheet trial, is that when I publish my workbook in HTML view, the charts that I have created within Zoho do not show. Whilst in editing mode I can see the charts correctly, in HTML view the charts are replaced by an image not found logo. 

Did I do something wrong or is this a known bug?