Answering your question on the inconsistent back button, there are simply too many of them. Sometimes it is the small text link with an arrow in the top left corner, sometimes it is a built in app back button, and sometimes the text version sticks around during navigation for no reason until it is clicked accidentally and throws back to the previous app.
I mean... I have several android tablets and have the exact same issue on those as well. Not sure how Android solves anything here. Except that you also get the hardware button that sometimes does absolutely nothing, or it goes back to a different location than the back button on screen.
Answering your question on the inconsistent back button, there are simply too many of them. Sometimes it is the small text link with an arrow in the top left corner, sometimes it is a built in app back button, and sometimes the text version sticks around during navigation for no reason until it is clicked accidentally and throws back to the previous app.
I mean... I have several android tablets and have the exact same issue on those as well. Not sure how Android solves anything here. Except that you also get the hardware button that sometimes does absolutely nothing, or it goes back to a different location than the back button on screen.