My Grav is set up as in the help documentation but also the GTmetrix site reports some css and js without compression and Leverage browser caching is not specified expiration for css and favicon.ico.
I don't know what to do about it I use the gantry framework for frontend.
I read this topic /forum/installation-hosting/how-to-set-cache-control-for-images-t4016 but I don't use NGINX so I didn't try it.
I have tried this on this topic /forum/archive/css-js-minify-not-working-t5186 and it seems to solve the problem of caching expiration, however it did not resolve the compression.
/assets/b4ccdc47e25cebc0f1a09dfe499d1f7d.css
/user/plugins/gantry5/assets/js/main.js?5dbd0b47
Apparently looking files are not being compressed, but performance improved after enabling Pipeline.