I gave the direct deposit information when I applied for dependent benefits for my kids. Their back pay checks just magically appeared one day. The direct deposit and subsequent checks still haven't appeared.....5 months later. They sent me a letter (as custodial parent, to my house) saying they couldn't send the checks because they don't have the address. Huh ?

One of these days, I'll feel decent and haul my butt over to the SS office.

I think you should go to your local ss office and make sure they have the paperwork for your son to get benefits and that they have your address, not your ex's to send the checks too.

Good Luck !