[slowsmile]

@st_albert...On conversion to epub, the individual chapters are selected and a file split occurs in the html file if they are correctly formatted and styled with "Heading 1" style(h1) in OO or LO. Your h1 headers can either be directly styled with h1 or your named style can also be linked with h1 to be selected. Your "Heading 1" style in OO or LO should always be linked with "Heading" style in the Styles Organizer. Do not link h1 style with "Default", "Text Body" or any other style in OO or LO.

If that doesn't cure your problem, could you please attach your html file and attach the equivalent in an ODT file in your next post showing just the problem area -- consisting of just one complete chapter with heading -- in your next post so I can have a look at the formatting?

I suspect that your h1 style has been set up in the wrong way in OO or LO regarding inheritance.

Just to also mention that you should be linking all your own named text styles(text styles only, not headings styles) with the "Text Body" style. Doing this will ensure that all your own named text styles or classes will appear in the epub html in Sigil. So doing this prevents all your inline text styles from automatically being converted to meaningless prefixed/indexed style names like ebk-3, ebk-12, ebk-23 etc.