keyboard navigation on login page not working adequately

### Description

on the login page (if auth is enabled), there is a problem with the keyboard navigation

the page loads with the prompt in the username field --> this is good
with tab key, the prompt moves to the password field --> this is also good
with subsequent tab key, the expected behavior is for the prompt to go to the login button, but it doesn't --> not good

the only way to click the login button is with the mouse. this is doable, but quite annoying.

is there a way to fix this please?

Start by locating the login page implementation and reproducing the issue with authentication enabled. Inspect the keyboard tab order after the username and password fields; done means the login button receives focus on the next Tab press and can be activated from the keyboard.

Written by the indexing model from the issue text.