Hello, we apologize for the issue you are facing with Instant Indexing. To troubleshoot this, please ensure that the Instant Indexing module is enabled in your Rank Math settings. You can do this by navigating to WordPress Dashboard → Rank Math SEO and checking the module settings.
If it is enabled, you can try submitting your posts for indexing again by hovering over the post on the Posts page and selecting the Instant Indexing: Submit Page option.

Additionally, you can check your page’s index status within your WordPress dashboard by going to Rank Math SEO → Analytics → Index Status.

If you continue to experience issues, please reply to this ticket, and a human agent from the Rank Math Support team will assist you further. Thank you for bringing this to our attention!
Sources:
How to Fix "Crawled – Currently Not Indexed" Error in Google Search Console » Rank Math
Hello,
Thank you for contacting us and sorry for any inconvenience that might have been caused due to that.
Could you please share some more details about the issue you’re facing with Instant Indexing? You can also share a screenshot by using any image-sharing tool like https://imgur.com/upload so that we can check the issue further for you.
Looking forward to helping you.
Thank you.
Hello,
Since we did not hear back from you for 15 days, we are assuming that you found the solution. We are closing this support ticket.
If you still need assistance or any other help, please feel free to open a new support ticket, and we will be more than happy to assist.
Thank you.