Hello,
Thank you for contacting Rank Math and sorry for any inconvenience that might have been caused due to that.
When deleting URLs that are already indexed on your site, you should always redirect the URL to your homepage or a relative page to make sure they don’t lead to 404. You should also use Google URL removal request option to remove the URL(s) from indexing.
Deleting them without doing the above may lead to Google trying to update the URLs since they are already indexed which will most likely lead to issues such as the one you are facing currently.
Hope that helps. If you have any further question(s), please let us know. Thank you.
I have done Google URL removal request. Hopefully this fix the issue. Thank you very much!
Hello,
We are super happy that this resolved your issue. If you have any other questions in the future, know that we are here to help you.
If you don’t mind me asking, could you please leave us a review (if you haven’t already) on https://wordpress.org/support/plugin/seo-by-rank-math/reviews/#new-post about your overall experience with Rank Math? We appreciate your time and patience.
If you do have another question in the future, please feel free to create a new forum topic, and it will be our pleasure to assist you again.
Thank you.