Thread:Talk:Search/prefix: search for localized namespaces broken

The following queries stopped working with the new search. I guess it has something to do with the localized namespaces.
 * https://de.wikipedia.org/wiki/Special:Search?search=TMg+prefix%3ABenutzer+Diskussion%3A
 * Current result: Articles are found. It's like the prefix is ignored. When I try to use the namespace checkboxes instead they are ignored as well, as long as the prefix: is still in my query. I have to remove the prefix: from the query to make it work as expected. Isn't this strange?
 * Expected result: Only pages from the German "User talk" namespace.
 * https://de.wikipedia.org/wiki/Special:Search?search=TMg+prefix%3ABenutzer+Diskussion%3ATMg
 * Current result: Nothing is found.
 * Expected result: Only pages starting with "Benutzer Diskussion:TMg", obviously.