I129 Petition approved with past dates

I have received Approval notice with past dates, Approved from 10/01/2019-12/16/2019. With notice date 02/04/2020. In I797 they have mentioned I94 expiry date is 12/26/2019. Employer called USCIS regarding backdated issue, USCIS informed that they reopened my case very after the approval and recommended wait till reopen notice received. What should i do in this scenario ? Please advise. Thanks in advance.

Hi @Keerthan_Kommineni

Most people who are facing similar issue are filing a new extension with nunc pro tunc option.