Thread:Support/Old translation interface broken?

Steps taken:
 * use search
 * click on translate link for a result
 * open dropdown next to page name, select "all languages" (it's really awkward that that's the only way to select which language to translate to, by the way)
 * click on a message (this will bring up the old JS popup interface)
 * save

The page was saved successfully, but I got redirected to https://translatewiki.net/w/api.php with the content. It seems like something that used to be POSTed as an AJAX request is done via a normal browser POST submit now.