?purge=true restores content of that page. Seems to me the caching issue that recently is also fixed in master branch of data plugin. I guess that dokuwiki.org needs update of data plugin. When a filtered datatable is linked, the response is sometime cached, and also used for page requests without that url parameters. (see e.g. this commit:
https://github.com/splitbrain/dokuwiki-plugin-data/commit/56e07fd24f67672c6e956d0b330c5e14f28bf822, in pdo branch also fixed
(from Klap-in on devel:irc_meetup)