Hi Ken,
Thanks
I did similar to what you recommended.
Got my CSS style rules on screen as code.
Changed a font from px to %. Saved it. Went back to the CSS form version of the rule. For that rule I now have the full range of options available under "Type Font size"
However, other rules or new rules stay as px only until I same work-around as above. Then I get the full range of options.
Peter