Delta not getting refreshed while getting the option chain data

I am using the below api to get the option chain. This is today’s data.
Url used :

curl --location --request GET 'https://developer.paytmmoney.com/fno/v1/option-chain?type=CALL&symbol=NIFTY&expiry=30-01-2025' \
--header 'x-jwt-token:  <jwt_token>'

The ~0.25 delta was clearly showing wrong data @10:15 even is subsequent calls the prices were changing but not the delta