Need to fix the ‘Sitemap index can be read, but has errors’

I have a problem with my google search console sitemap it shows ‘
Sitemap index can be read, but has errors’.
Attached image for your reference to sharing the idea to fix the issue,
https://storage.googleapis.com/support-forums-api/attachment/thread-94417475-9308203849026683644.JPG

Also, find the sitemap details below,
https://storage.googleapis.com/support-forums-api/attachment/thread-94417475-9308203849026685777.JPG
I guess two sitemap URL does not have the last modified date that may be an issue, share the idea to fix the issue for WordPress site.
using the ‘Yoast plugin to generate the site map.

Thanks,

The page I need help with: [log in to see the link]