I have been a fan of firefox, and was introduced to it after I switched to Linux.
I resently installed firefox on my android mobile and was stuck by a particular bug or UI issue, whenever the toolbar is set to bottom and you search for something. Everything goes fine. Then you open a website. Now, here if you click on the toolbar(say you want to copy the url) the background(meaning space apart from keyboard and toolbar) is set to the firefox homepage which looks jerky as well as not good. A better way would have been if on clicking the toolbar the site you are currently in should be used as a dynamic(meaning still scrollable after toolbar is in focus and keyboard is open) background. See this is what I mean to say (https://i.imgur.com/IRMF3hq.mp4)