Is H4 extension required if i94 is already updated as per h1b i797

Hi

  • I changed my job in April 2020. At that time my family was in india.
  • H1b visa validity with previous employer is till September 20th 2020.
  • H1b validity with New employer till: January 31st 2022.
  • My wife and son travelled recently to usa in July 2020 on H4 valid till 20th September,2020.
  • However at port of entry she showed my recent I797 and they updated my son’s and her I94 till January 31, 2022.

Question:

  1. Do I need to file an H4 extension now as there i94 is already updated?
  2. Will they face any issue if they are traveling out of usa.
  3. How will my wife and son will get their i797 if applicable.

Can I expect reply on this one.