Getting mail at different addresses?

Hey guys, my brother got his 797 letter for the work permit at my parent's house & the deferred action one at his house. Any idea why? The only thing we can think of is that he put my parent's house as the return address on the envelope he mailed it in. But that makes no sense, shouldn't they be going off of whatever is on the actual application?

he should double check the address that he put on the apps?? The 821D had multiple section for addresses. Die he keep a copy of his app?

he should call uscis to fix it though.

Yeah check his applications. Did he use a different address in the 1797? and a different on the i82 something one?

I got different letters at different address. Actually at different states. I believe they use the address where I currently live. i797 was sent to my WA address and the i8 was sent to my OR address.