Blank site maps

I created 3 sitemaps on January 14. A map for the Thank You page had been created which I did not want submitted, so I then manually submitted the desired original site maps through Google Search Console, keeping them in public_html.

I have been unable to re-generate current sitemaps.

There had been a setting in WooCommerce admin which I changed so that HTTP Strict-Transport-Security is forced. I tried following the recap at the end of https://ww.wp.xz.cn/support/topic/sitemap-is-blank-2/ . I removed the sitemaps completely, disabled and re-enabled the XML sitemaps setting, purging the cache also, still getting blank pages.

https://www.sealeatherwear.com/sitemap_index.xml is showing 3 sitemap links but these all now go to blank pages.

The top line in each of the previous sitemaps was containing:
<?xml version=”1.0″ encoding=”UTF-8″?><?xml-stylesheet type=”text/xsl” href=”//sealeatherwear.com/wp-content/plugins/wordpress-seo/css/main-sitemap.xsl”?>

I have a staging shop and the maps do get created there. There were several plugins that the live shop has that the staging shop does not – Activity Log, Email Log, Koko Analytics and 301 Redirects. I installed 301 Redirects (without any settings) on the staging shop, turned off XML sitemaps, turned it on again, and the maps are still appearing in the staging shop.

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