Thank you for your offer to help. I recreated this issue in a new project. I created a new project in RoboHelp 9 and upgraded the project to RoboHelp 10. I followed your instructions and sent the source RoboHelp 10 files.
I suspect part of the issue is that your list styles have spacing above and below and then you have applied paragraph styles that also have spacing above and below.
Using both is OK and is how I work. However, I do not have any spacing above and below in my list styles. I rely on the paragraph style for that. It looks like Rh's Design Editor is applying both but browsers are not.
It is still not quite the same in a browser as in Design Editor but it is much closer. There will also be browser differences anyway so it's a case of getting some balance.
Try removing the before and after spacing in the list style. Alternatively, if you do not generate printed documentation then rely on the list style only. (Select the lists in a topic and set paragraph to None).
Let us know if that is close enough.
See www.grainge.org for RoboHelp and Authoring tips
I like your suggestion for only changing the spacing for the list styles and to leave the paragraph styles alone.
I made the adjustments to my list styles, and you are correct, the styles are not displaying exactly the same. However, I think it is something we can live with.
Again, thanks so much for your help and willingness to step in!