Clicking on the tag “open thread” on this post only shows open threads from 2011 and earlier, at “http://lesswrong.com/tag/open_thread/″. If I manually enter ”http://lesswrong.com/r/discussion/tag/open_thread/″, then I get the missing open threads. The problem appears to be that ”http://lesswrong.com/tag/whatever/″ only shows things posted to Main. ”http://lesswrong.com/r/all/tag/open_thread/″ seems to behave the same as ”http://lesswrong.com/tag/open_thread/″, i.e. it only shows things posted to Main, despite the ”/r/all”. Going to “article navigation → by tag” also goes to an open thread from 2011, so it seems to also ignore things posted to Discussion.
Clicking on the tag “open thread” on this post only shows open threads from 2011 and earlier, at “http://lesswrong.com/tag/open_thread/″. If I manually enter ”http://lesswrong.com/r/discussion/tag/open_thread/″, then I get the missing open threads. The problem appears to be that ”http://lesswrong.com/tag/whatever/″ only shows things posted to Main. ”http://lesswrong.com/r/all/tag/open_thread/″ seems to behave the same as ”http://lesswrong.com/tag/open_thread/″, i.e. it only shows things posted to Main, despite the ”/r/all”. Going to “article navigation → by tag” also goes to an open thread from 2011, so it seems to also ignore things posted to Discussion.