Hello,
Thank you for contacting us and sorry for any inconvenience that might have been caused due to that.
Please note that Instant Indexing only submits the URLs to Google so they can be crawled faster and potentially indexed but still, it solely depends on Google if they want to index a URL or not.
You can test some of your pages in the URL Inspection Tool and share the screenshots of the result with us so that we can check the issue further for you: https://support.google.com/webmasters/answer/9012289?hl=en
You can use any image-sharing tool like https://imgur.com/upload to share the screenshot.
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.