Closing Firefox Preview on Android 7.1.1.
I am using Firefox Preview 5.1.1 (5 June 2020) on a Sony Xperia Z5 premium phone with Android 7.1.1. This behaviour is also occurring on my older telephone a Sony Xperia M5 Android 6.0, and it has the slightly older Android Preview version 5.0.0 version on it from 30 April.
I use the Google Now launcher, Firefox Preview is set as the default browser. When I use Google Now to read the news, or search using Google and view the resultant webpages in Firefox, this works well, until pressing the back button in Android to close the browser, the browser always goes back to the open tabs page. One more back press closes the browser and returns to the calling Google app.
This is fairly recent feature that seems to have arisen, and is not shared by the current Firefox for Android (68.8.1).
I have Ublock Origin installed in both versions of Firefox on the Z5. This however does not appear to affect the described behaviour.
I prefer the other features of the Preview edition, it is quicker among other things and would prefer to continue to use this as the return to the Open Tabs page is a minor inconvenience, but would wish to revert to the older behaviour if possible.
Prior to the 5 June update, there were also frequent crashes in the immediately preceding version, at what appeared to be this same point, and Firefox Preview would request Close or Restart. This seems to have been fixed in this later version.
I hope there is a way to prevent this behaviour, perhaps by some configuration I haven't been able to find, or perhaps this is just the way it is designed.
Thanks in anticipation of any reply.