This is a known problem on Android 6.0 Marshmallow with form fields when you open a page from any of Firefox's home screens (bookmarks, history, top sites, previous tabs). A bug was filed for it on Oct. 6th, and there will be a fix for it in Firefox 42 for Android. The current Firefox Beta app in the Play store does not yet have the fix, maybe by the end of the week. For now, the quickest workaround I've found is: menu > Reload Other reported workarounds take longer: * lock and unlock the screen (off and on alone doesn't do it) * rotate orientation and back again (doesn't work on mine) * load pages using the address bar (type a few characters then autocomplete) Related thread: [https://support.mozilla.org/questions/1089432 Bookmarked links for search engines not activating keyboard after updating to Marshmallow].