Ideally the list should display properly in both the outputs. However, it seems to be an issue specific to some characters used in the list. It will be great if you could share the autonumber definitiion(s) in the FrameMaker document paragraph style. It will be even better if you could share a small sample FrameMaker document having such a list. You can upload the document (may be at acrobat.com) and share the download URL.
This will help us investigate the issue at our end and provide the appropriate solution accordingly.
Thanks for the reply.
Here is a link to a representative FrameMaker document: https://acrobat.com/#d=*NcuV00rWjZPnOKhYewjeg
The FM autonumber format is an interesting theory, but I'm not sure that's it. If bulleted or numbered list is in a table, it displays fine. Outside of tables, bullets and numbers are nowhere to be found.
Here is the CSS that is being applied to the topics when they are generated in case that helps: https://acrobat.com/#d=HYslhpcR2-3ERIyi6-fzNQ
Since you mentioned the issue with Wingdings font, I am assuming that "sn Step Number" character style is being mapped to BulletSymbol character style(in fmstyles.css) which makes use of Wingdings font. (Please verify in Conversion Settings dialog)
Since Wingdings font is being issued, the symbol displayed for bullet comes from Wingdings family when viewed in IE. However, as Firefox does not support Wingdings properly, a normal character is displayed in placed of a Wingdings one.
In case Wingdings character is not required, it is recommended to either modify the style BulletSymbol to use some other font or map "sn Step Number" style to source. Also, "Convert to text" option seems to suit your requirement. So, it is recommended to use that particular setting for "b bullet" paragraph style.
I hope that resolves your issue. Please let us know if you have further queries or you face further issues.
I changed CSS references to Wingdings to something like Arial and set the autonumber to convert to text, and that did the trick. I don't like that my bullets and numbers are now inline rather than hanging, but I guess I'll need to create new paragraph styles for my numbered and bulleted lists rather than relying on the regular body paragraph styles.