FAQ is not showing on Amp whereas showing on NON-AMP

Hello,

Thank you for contacting Rank Math, and sorry for any inconvenience caused.

I checked this URL with the Rich Snippet Tool and it got validated without any issues and the FAQ schema is also detected:
https://chapraonline.com/land-record-bihar-online-registration-2021/amp/

Please note that it is completely up to Google to show the FAQ schema on the search result page, as it depends on the search keyword and competition on that keyword.

I have already checked the URL and it is valid for AMP.
To check if the page is valid for AMP, please check the page at https://search.google.com/test/amp

I hope this helps. Looking forward to helping you.