Unemployment during stem extension in process

[UmaVP]

My OPT STEM Extension expires on Oct 8 2018 and I will be submitting my STEM Extn application in a week. Once I submit and get a receipt notice, I understand that my EAD will be auto extended for 180 days. During that 180 days  ie) after Oct 8 2018, while my extension is still in process if I lose my job , will my OPT Extension be denied or Will  I be still be eligible since I have not exhausted the 90 days of unemployment during my OPT? Please advice.