**Expected behavior **
GIVEN I am successfully logged in on the **desktop** site, e.g. https://www.wikidata.org/
WHEN I open the **mobile** site, e.g. https://m.wikidata.org/
THEN I am logged as the same user
**Actual behavior **
GIVEN I am successfully logged in on the **desktop** site, e.g. https://www.wikidata.org/
WHEN I open the **mobile** site, e.g. https://m.wikidata.org/
THEN my logged in status is **not** detected and I can **not** make use it
**Technical insights**
When opening the mobile login page, e.g. https://m.wikidata.org/w/index.php?title=Special:UserLogin&returnto=Wikidata%3AMain+Page&returntoquery=, the requests that try to facilitate the login can be inspected.
Apparently requests get sent against login.wikimedia.org but are responded in a wrong way for the wikidata domain - the `Location` header instructs our browser to connect to "https://www.m.wikidata.org/..." which is incorrect (**stray "www."**).
{F29536308}
Applies to both production and beta.