after I 130 interview, our form sent to local office

[ngathet]

Hi,
Me and my husband got I 130 interview on late June and on July our form was sent to local office for officer review ? Is there anyone know why they send it to local ? It's been so long like 3 months and we still didn't know the result yet . Our interview went very well and but delaying in result . Is there anyone who got same experience with us ?