As far as I know this plugin is working fine (thank you), and Google is using sitemap.xml and sitemap.xml.gz both of which I "submitted" myself. (Although perhaps I should remove sitemap.xml as it doesn't need both.)
However, Google also keeps trying to download a non-existent sitemap file, wordpress/sitemap.xml.gz
Since it isn't one of the filenames I submitted myself, Google won't let me delete it from the list of sitemap files. I keep hoping Google will realise the file is not there any more but it's still trying to download it after many months.
Google still has 42 pages indexed from the old (non-existent) sitemap file - and of course all those pages are non-existent now so I want Google to forget about them.
How can I get Google to use only the correct sitemap file?