On our private server we have Site Ground optimise, WP-Members and Members plugins. There’s protected page which when we go to it prompts for a login.
This used to work fine, but now since some updates I guess, it no longer shows the two factor auth page. Logging in to /wp-admin does show it.
Inspecting the code shows this (below), removing the ‘display:none’ allows the user to login.
.login-action- > div#login:first-of-type {
display: none;
}