Berth multiplexing means using of unused seats b/w source to intermediate station which share the same quota as of Origin to destination. Here HWH - ASN and HWH - PNBE share same GNWL. So, someone might have booked a ticket from ASN or any other station station after ASN which meant that seat was empty in HWH - ASN stretch. You got that seat as CNF. And HWH -PNBE waiting list would hav been WL 10. And since ASN shares quota with Patna, you got WL 10,11 instead of WL1,2.