Also, it does not log me in because if I try to go back to the page I was browsing, I still see no login. (there were times only the redirect was broken, not this time)
Before doing that, I tried it again. using the “login” page from MDBU is definitely broken. Or it is the login page that is broken if extra parameters are given.
I used the direct link to login page from “Cloud: MongoDB Cloud” link. It has no redirection parameter and it worked. I visited MDBU but did not auto-detect my login. Then I used the sign-in button there, and finally detected login.
Anyways, I will send an email to “Learn” but maybe you too let the login page team know about this incident.