My employment with company A ended on Dec 21st 2018, but I have the pay slip until Dec 30th, during my grace period have found the job with company B and applied for H1B transfer on Feb 12th (USCIS received the packet, have Fedex tracking) to Vermont center but I received the Receipt notice dated Feb 28th 2019 from California Center.
Even though the transfer petition is filled within the 60 grace period the receipt date is after 60 days.
Were you laid off or you resigned from your job or what exactly happened? H1B 60 day grace period is only applicable in job lay off cases.
USCIS decision will be final in your case and we have seen cases where USCIS simply said that they received the application on the date they have generated the Receipt number.
Generally, Fedex delivery is considered valid but off late, we have seen that USCIS simply denies the delivery.
Talk to your attorney to know the risks.
As per my opinion, you should leave US and wait for transfer result outside USA.
USCIS will count your time after 61st day to the USCIS receipt date as the ‘out of status’ time.