vh-- After time for reflection, here is my best guess as to what happened. Express VPN occasionally loses its connection. I believe the scammers have their wifi configured to immediately take over when Express or another VPN goes down temporarily. As I said, I got frustrated and entered a password when Express was telling me not to do so. (Didn't recognize the signal at the time) On my end, the lesson is to never use any wifi other than that provided by a known entity. (Which gets me worrying about those who could mimic a store or restaurant's or airport's wifi for example)

As I said before, I put very little financial information on my android tablet and have many email addresses not associated with my real name to fend off thieves. Which seems to have worked in this instance.