I found a solution, but not an ideal one.
I had to clear the TypeKit from the Webflow Font Site Settings and then add the embed code from the Typekit website to the header, and change the async from "true" to "false"
This is explained on a Typekit help page: "If you would prefer to have the page wait for the fonts from Typekit to be available, you can use the script tag to block the page render and prevent any chance of FOUT; remove the async: true option or set it to false."
The only problem now is that my futura-pt font does not render properly in the designer. It's not the end of the world, but would be great to figure out a way to be able to change the async setting to false and still have the font available in the designer.
Any thoughts on this?