I am using custom CSS to style a gravity form I’m using on my website. After editing the CSS in the Global Editor the site preview displays the changes correctly. After saving and publishing the changes remain. BUT after I reload the page, the changes disappear and the form reverts to its original style.
If you are adding the CSS into Global settings section, why you are not using the Theme Customizer -> Additional CSS box. Move the CSS from global settings and check once.