i cannot describe this problem clearly. it's kind of my habit. my firefox used to be able to do this: when i want to search something in the webpage, i don't need to tab Ctrl + F, instead, i directly type the content, the search bar will appear automatically and show me the result(if there is not type zone receiving data). however, last night i installed new firefox instance in another computer and synced it to my account, i found this functionality didn't work again. i don't know it's a little feature of firefox or it's backed by some sort of add-on. if somebody knows why, please let me know.