Last modified: 2014-05-06 16:31:47 UTC
Created attachment 11388 [details] New messages on mediawiki.org Looks like Echo broke NewMessages further?
Hasn't been always the case that threads were sorted by age of the thread, regardless of the age of the last posts in those threads? Your screenshot follows this pattern. Definitely not a standard behavior, but maybe this is how it was designed.
Lacking more info, I'll assume Quim is right.
Resolving as WORKSFORME, then.