Default H1B Extension approved but I-94 not updated in the system/online

Hi,My first petition expiry date/visa end date was until 18-Jul-2017. I had applied for H1B extension in April -2017 and got the approval in 15-Sep-2017 (before to the 240 day grace period of my I-94 expiry date- 18-Jul-2017).The new petiton that I received has petiton end date is 11-Apr-2018 and I94 end date is 21-Apr-2018. I am currently in US and haven’t travelled to India since my first arrival here.Now, I am applying again for H1B extension but when I verified my I-94 details through https://i94.cbp.dhs.gov/I94/request.html , it still shows my I-94 end date as 18-Jul-2017.It seems end date hasn’t been udpated yet. I know that if travel to India and come back,it would be updated at POE. But only with I-94 extension, shouldn’t the update be done in the online system?Is this fine or I need to take any type of action.Thanks a lot for your response!