rarest of rare cases
Hi
First of all here's hoping that you get approved shortly too. Anyway, my wife's 485 (derivative) got approved last year while my Namecheck was pending. She got her PP stamped also and in fact travelled to India twice with the stamped PP. When it was over 9 months and still didn't receive her card, took an infopass appt to find out what the matter was. Was told that her case somehow slipped thru the cracks and got approved by mistake as primary was still pending. In the meanwhile, my case was impacted by retro, so no chance of my getting approved till PD became current. So they told my wife that USCIS would cancel her approved 485 and she needed to apply for EAD/AP again, which she did and got approved. Till date we are stuck in the never ending loop of EAD and AP. So I can only wish you good luck in this rollercoaster journey of GC.
Cheers !