L2 EAD Renewal clarification for Work authorization

[Sudk225]

My L2 EAD expired on March 6 2018 under category a18. The acknowledgment receipt for renewal a18 was received by March 5 2018. The receipt did not allow 180 day automatic renewal and authorization for work. My husband had applied for green card on March 27 2018, which provided me EAD receipt under category c 9. Can this receipt be used as work authorization? Clarification: as per the new rule, this c9 cannot be used as extension for a18. And this c9 was not filed before the expiry of the EAD. So can it be used as work authorization?