A very similar issue is happening with my Box on OFW 2.0.6. After I've installed Firefox, after every reboot, an action pop-up menu appears on the bottom of the screen, like something had triggered a web-browser related action, saying to "Choose Firefox or Google / Just once and Always", if I choose one of them it will open up the web-browser. Pushing simply the "Back" button will juts close this pop-up. Jess, I have also Google from PlayStore installed with it's search bar visible on the Home Screen.
It also happened once after I've started a video playback from KODI with Wrapper, and it won't start the video and have to push "Back" to exit back to chrome. starting the video again and everything was back to normal.
Presumably if I would uninstall Firefox it will fix the issue, but I wouldn't want to, cause I've installed it whit a purpose.
Have anybody else experienced this problem, and what would be the solution in this case?
Edit.: I will try to to choose "Google" and "Once" and see if it remains untriggering anything unwanted.