Where is the css file for the search icon like in this picture http://prntscr.com/o68cwa? I want to exclude it from the wp rocket. Because after I upgraded the plugin, the search icon didn’t appear.
it uses a font in your current setup – if you Browser inspect your page ( Right Click > Inspect ) you will see a bunch of 400 errors for the fonts it requires. The URLs it is calling from are incorrect. They are being called from io.wp.com which i believe is Jetpack Photons server. Not sure why they would be trying to server the font but you can try excluding those files from Photon.
I saw that Photon was updated, now called Site Accelerator which also grabs any static files so maybe when WP Rocket was updated the cache was cleared which allowed photon to grab the font files.