By default, browsers don't render text if the font isn't loaded, which slows down page rendering.
NitroPack instructs the browsers to render text as soon as they can, and then swap the font of the rendered text when the font becomes available. This makes for a very fast page rendering, but the font swap is often visible to the users.
If you want to disable this feature and keep the default browser behavior where text is rendered only after the fonts are loaded you can do the following:
1. Log into your account at https://nitropack.io/
2. Navigate to the Settings section
3. Move the optimization mode slider to Manual
4. Switch to the Advanced Settings tab
5. Click Additional options under the Optimize CSS Delivery option
6. Set Remove @font-face rules from the critical CSS to Disabled
7. Disable the Override font rendering behavior option by using its slider toggle on the right
8. Save the changes and purge your website's cache from the Dashboard