Hi all,
Wikidata is planned as a multilingual resource, and we are using ULS for switching languages. ULS is pretty cool, if you have not tried it out yet, you definitively should. ULS works great if you are a logged in user. ULS on Wikidata does not work so well right now if you are not logged in. Due to caching issues, the system sometimes switches your language randomly.
There is a bug with quite some discussion going on: https://bugzilla.wikimedia.org/show_bug.cgi?id=41451
There is a changeset to ULS providing one solution: https://gerrit.wikimedia.org/r/#/c/32030/
There seems to be an agreement that the solution could fix the issue for now with Wikidata, but it is unclear if this will scale to the Wikipedias. This is a call for some input and attention to anyone who can help resolve the issue.
So far huge thanks to Daniel K., Mark, Niklas, Katie, Siebrand, Faidon for pushing for solutions.
Cheers, Denny