Yeah, happy that it is not the end of the world security wise, but probably should not be a setting left flapping in the wind after releases. A sense/perception of additional security is not unimportant
None of the other toggles go off, but then they are maybe held centrally rather than on the phone
This has happened to me too. Around 4 times in the last 5 days. Doesn’t seem to be any rhyme or reason to it apart from possibly something to do with the length of time since I last re-enabled it.
This is becoming pretty tiresome, I am having to switch this back almost every time I load the app !
Been happening to me for several days on a Pixel 2. Really poor from a security perspective!
Just updated this morning to the latest beta and it disabled it again 
It’s been happening with me for a few weeks. I enable it then a couple of days later when i go to check something it’s disabled. Annoying!