Google Knowledge Panel for Music Artist

Do a search for "DD Allen" and you see there is no knowledge panel on the right hand side of the Google search results page. Moreover, despite all our efforts, there is now a Google Map location appearing on the rh side suggesting there is a local business account rather than a brand page. We have connected accounts with consistent vanity URL's but something is obviously missing in the set up. A Google Plus Brand Page A linked website A You Tube Channel All hooked up with a custom URL But something is clearly wrong and we cannot get to the bottom of it.