Hi,
i tried the same and even when i added the css code above to my main stylesheet google pagespeed tester is still showing that issue on my site.
On this page it says that you have to do an additional task to make sure the pagespeed-speed issue will not come again: https://web.dev/font-display/ (Headline: Google Fonts in the middle of the page).
Where do i have to add that: &display=swap parameter on my site?
My Site is https://www.nebenbeionline.de and i want to make sure that my Site is running fast like hell :).
regardly
Ferhat