When I'm not logged in and watch at articles as German IP outdated revisions of all articles which were edited within the last four days (in every language version of Wikipedia) are shown to me. Also when I look at the revision history I can (as IP) not see all recent edits. Often the revision history is more outdated and does not even show the outdated revision which is shown. Sometimes I can not see edits since 23 January and sometimes I can see edits from 23 January but not more recent edits. When I edit a page as IP I can see the current revision and all revisions in the revision history. But when I delete the cookies or just use another browser I can again not see the recent revisions of this articles. Purging does not have any effect. (I just tried again to purge 1 minute ago)
For example [[:es:Federico Macheda]]
When I am not logged in I see an outdated revision of 21 January which contains vandalism. Also in the revision history I see only revisions until 21 January.
At [[:en:Federico Macheda]] I see an outdated revision of 24 January and the revision history only contains revisions until 23 January.
The same problem concerns nearly ALL articles which were edited since 22 January. When I am logged in the problem disappears. But when I log out and delete cookies again I see the same old revisions and outdated revision history.