Correct. To be fair, though, I am running the authenticator app on a piece-of-crap Obamaphone that they give to low income people for free at the Social Services offices. It’s an “Alcatel” A464 running Android 4. Thing’s the size of a playing card, and it suuuuuuuuucks.
But, I’ve downloaded and installed, and am running, the authenticator others describe. My screens look like Perl’s above.
I do too! When I head to the Play Store right now (on my PC), the Authenticator says it is compatible with all my devices, which is this piece of junk Alcatel, and another LG Stylo that I use only on wi-fi. It, too, is many years old (older than this lifeline phone), and had the authenticator on it for a long time before I switched it to this phone (the only phone I have that has 4G access.)
Something else is up, I think, besides phone and OS versions.
Changing your percieved IP address by going through a variable ip vpn or by any one of a half dozen different different ways can also trigger authentication.
The system “learns” your normal ip block of numbers and deviations from it will kick off the authentication routines.