Parents H1B visa stamp expired. CKGS returned application for minor passport renewal

Hi, I am living in US on H1B which is valid upto Jul-19 but my Visa is expired to enter in US.

CKGS is saying Visa is expired of Parents and parents status is not legal but our H1B is valid. Now what can I do to get approval of this application.

What US legal status proof did you submit?

The H1B visa stamp in your passport OR the approved i797 (which shows the H1B was extended and is still valid)?

I submitted US Visa copy which is expired but H1b is valid till July-19.
I hope if I send I-797 copy then they will accept it.

Yes, you have to send i-797 copy that still has validity.

Also, when you start your application, select the i797 as the US legal proof document and not visa stamp.