Update:
I have the same problem on MacOS and Firefox. With Safari, I'm able to log in. However, since my work device is Ubuntu, I don't have the option of installing Safari on it.
It seems to be broken again.
I am on Firefox and Ubuntu 18.04. I was previously able to log in after disabling ALL privacy blockers (the necessity of which is a huge black mark in our eyes, btw), but now I'm not able to log in at all. Whenever I hit ...