Thanks to the discussion I now can see and describe my problem clearer.
When using line-fill-mode it does not take the current org list
indention into account. Because of this org lines like this will appear.
- one entry with a very long text ending in the second line
end
- second entry
This is recognized (e.g. while html export) as two one-item-lists with a
paragraph between them.
When I press RET myself the point is correct indented but not when it is
done automatically via line-fill-mode.
Is there a solution for this?