Yaşadığınız sorun için Rankmath'in support staff'i bunu yazmış.

Alıntı

Hello,

Thank you for contacting us and sorry for any inconvenience that might have been caused due to that.

If you are getting the 404 error it means that the URLs are not in the Indexing API. Since the API is only for two types of websites (job posting and live streams) and goes through rigorous spam detection due to recent changes in Google, it’s much more difficult to get URLs into the API.

So, unless you have one of the website types we mentioned and the content is unique, you won’t be able to use this feature consistently and you shouldn’t as the API was never intended for it as mentioned in our own documentation.

The bottom line is that our submissions to the API are working fine, but if the pages are not accepted into it because of guidelines issues, there’s nothing we can do.

Please don’t hesitate to let us know if you have any other questions.
Yani "bu özelliği tutarlı bir şekilde kullanamazsınız"
demiş.