Can’t log in?

Has something changed with the WP login? For both of my sites, I’ve been logging in by going to the following address:

https://customyarn.com/blog/wp-login.php
https://yarniapdx.com/wp-login.php

All of a sudden when I try to log in using either of those addresses I get a 404 error message.

I noticed that some of my sites auto-updated to the new version yesterday–did something change with this login perhaps that is causing this to happen?