New plugin version breaks sitemap?

We had recently migrated from https://www.himpro.ca to https://himpro.ca. We have 301 redirects in place.

We also updated to the latest Yoast SEO plugin version. The sitemap xml pages are all empty (no urls show, but the header does). We have tried refreshing the creation of the sitemap (disable / enable sitemaps), deactivate / reactivate plugin, but it did not work.

>>> We have now disabled sitemaps from your plugin, and using another XML sitemap plugin in the meantime. (so it’s normal you will see a 404 if trying to access: https://himpro.ca/sitemap_index.xml)

Given the situation I describe, do you have an idea what might cause the issue with the sitemap of your plugin?

thanks

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