Hi @Chirag Gulati,
Per my research, you need to check if Allow this site to appear in Search results is set to Yes. Please refer to following steps
https://learn.microsoft.com/en-us/sharepoint/troubleshoot/search/search-results-missing
Then you will need to configure search filters and search results in the following article
https://www.gravityunion.com/blog/how-to-configure-simple-pnp-search-on-sharepoint-site
Since the pnp search is a 3rd part tool. And I am not familar with the issue. I would recommend you to raise a new ticket in pnp-modern-search github forum. This is a forum dedicated to discussing pnp search. You might get some more professional advice there. Thanks for your understanding.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.