Autofill doesn't play well with apparent PG&E website change

The https://myaccount.pge.com/myaccount/s/login/?language=en_US (Pacific Gas and Electric) seems to have updated in a way that prevents the browser extension's autofill from working. Instead of logging me in, it instead pops briefly to PG&E's OTP request page, then bounces back to the login page. (Click Sign in another way to see what the OTP page looks like statically.) Worse yet, the redirect URL in the address bar gets annotated with my username and password in plain text! 😱 I've since changed my password in an abundance of caution.

https://myaccount.pge.com/myaccount/s/login/?language=en_US&username=*****%40***.***&password=************