If you use a third-party theme for your Magento 2 store and have enabled "Use Magefan Blog Comments" as a blog comment option and flushed the Magento cache

Magneto 2 Blog Comments

but you still cannot see the comments on the blog post page on the storefront, please compare layout file blog_post_view.xml in your theme folder

app/design/frontend/ThemeVendor/themename/Magefan_Blog/layout/blog_post_view.xml

and the original blog_post_view.xml layout file from the blog extension code.

app/code/Magefan/Blog/view/frontend/layout/blog_post_view.xml

or

vendor/magefan/module-blog/view/frontend/layout/blog_post_view.xml

you may have missed XML nodes in the theme layout.

Correct theme layout file, save changes and don't forget to flush Magento cache again.