Why consulates put cases in Administrative processing even after approving the visa

[waitingforpp]

I had H1b stamping (f1 to h1) interview on 22 Dec at Delhi consulate. VO said visa approved and you will get your passport in seven days. Its still in admin processing. Status date changed three times but same status: AP

22 Dec : interview
26 Dec : admin processing
3 Jan : admin processing
12 Jan : admin processing

I have already cancelled one flight.

[miawright]

I had H1b stamping (f1 to h1) interview on 22 Dec at Delhi consulate. VO said visa approved and you will get your passport in seven days. Its still in admin processing. Status date changed three times but same status: AP

22 Dec : interview
26 Dec : admin processing
3 Jan : admin processing
12 Jan : admin processing

I have already cancelled one flight.

I applied for the visa from F1 TO H4 on December 5th, status changed December 26th, January 2nd and 3rd but still in administrative proccessing. VO said its approved and I should go get the passport after a week, please advise once you receive your passport.