I uploaded the Lato Google font locally and changed all the fonts in Webflow Designer. When I test our page in Page Speed Insights, the tool still tells me that I need to use font-display to Google Fonts even though I’m not using one anymore:
It seems like you have 367 unused classes. Some of those classes still contain “Font-family: Lato”. Classes like: Nav Link, serphhead_smallheading, Text Block 4… Just to name a few.
I recommend cleaning up the unused classes and see if the issue persists.
More info on how to Remove Google Fonts in this article.