H4 Approved H1B Transfer no receipt yet

[H1BVisa11]

Hi,

My new employer applied for H1 transfer along with H4 using premium processing. The application was submitted on 24th Aug; we received notice for H4 on 28th Aug and H4 approval on 04th Sep (copy of approval notice delivered by mail on 08th Sep). However, the attorney has not received receipt from USCIS for H1B(I-129). 

Any ideas why it might have happened? Also, is it safe to assume that H1B transfer would have been approved because H4 was approved.

 

Thanks!