The URL template contains no non-ascii characters. But my reading of what you posted shows there is no encoding being done (such as to latin-1), so while the result does indeed have no non-ascii characters (to allow QUrl.fromEncoding to not blow up), it also doesn't actually give me a usable result
Frigging encodings, hate 'em, grumble. I don't understand why this is all breaking now when it used to work fine (the reason the plugin comes with it's own right-click test menu with 4 sets of data on the configuration screen is because I used it to test exactly this scenario with exactly that title in the past).