Hello…. there is not an option to turn post comments on.
Is there a fix?
There is that “Disable comments sitewide” option in the theme panel. I haven’t used it and I’m not sure what it does on top of WordPress’s own (Settings -> Discussion -> Allow people to post comments on new articles), but it probably only affects the display of the comment section and not its functionality.
If you already have that theme setting turned off, check to make sure the WP setting allows comments. If both of them are right, the problem I think you’re noticing is that it doesn’t affect existing posts.
Each post also has the option to turn comments on or off individually. This is tedious, but you can speed it up by going to “all posts”, selecting them, and choosing “bulk edit” under the “bulk action” dropdown. After you apply that, the bottom right has a “comments” dropdown that you can set to “allow” or “do not allow”.
Does that help?
You may find it useful to review the WordPress docs on using comments to review all the options beyond just on/off in the WordPress settings > discussion …
