Trying to translate a encoded path or a path containing a query string, returns a no match error.
If you have a page called /press-releases that translates to /fr/communiqués de presse and then visit this /router/translate-path?path=/fr/communiqués%20de%20presse this will work as expected. If you append a query string, a random cache buster for instance i.e. k=131. You will get a no match.
If you now try visiting /fr/communiqu%C3%A9s%20de%20presse a path that was encoded before submitting the requests from a Drupal Next instance, you will also get a no-match, as it isn't being decoded before doing the alias lookup.
By adding something like $path = urldecode(parse_url($path)['path'] ?? $path); to the onPathTranslation method in RouterPathTranslatorSubscriber.php, we're able to resolve this above issue.
Needs review
2.0
Code
Same problem also on RouterPathTranslatorSubscriber. Attached a modified patch and the interdiff