Steps to reproduce:

• as a logged-in user visit https://meta.wikimedia.org/wiki/Special:UserLogin/signup
• check "Use a temporary random password...", fill out the rest and submit
• as a non-logged-in user, visit https://www.mediawiki.org/wiki/Special:UserLogin, enter the username and the temporary password

Expected behavior: the temp password is stored in the centralauth database and works
Actual behavior: the temp password is stored in the metawiki database and does not work on mediawikiwiki