UPDATE 2018-02-17 Sat: GOOD NEWS: I got back in. I had changed my phone's clock recently to "network time" as sometimes texts would arrive "before" the one I had sent that they were in reply to. Turns out that broke Google Authenticator. If you happen to do this, here's the fix: tap the "..." (menu) icon, go to Settings, which has two choices: "About" which opens a tab in your browser to describe the feature, and "Time correction for codes" which will reset the internal clock of the Authenticator app, which worked perfectly.

Odd, though, that WEX worked every time. And still does!

EDIT/UPDATE 2018-02-16 Fri: apparently Binance is affected as well. I was able to log in to WEX just now, so it's not "all Google Authenticator sites are closed to me", only 2/3 of my exchanges... :(

Whole story is in the title. I've opened a ticket, for them to ignore like all the others.

Be careful out there!

May your trading be profitable -- financially, spiritually, and emotionally.