lock box confusion/485

[doceb2]

This lock box thing is totally confusing.

These are the instructions

Spouse or child of an immigrant who has applied for adjustment of status or has been granted Lawful Permanent Residence through a Family Sponsored Visa category that allows derivative status for spouses and children; CHICAGO

6. A pending or approved I-140

You must include a copy of the Form I-797, showing that your Form I-140 was accepted or approved. PHOENIX/DALLAS

I thought Chicago lock box is for family based 485 applications and employment based 140 approved 485 petitions should go to either phoenix or dallas lockbox based on their state they live in.

I live in in Missouri ,so it is Phoenix lock box I thought, Any advice appreciated.