I think you'll be able to keep the 2800. I read that section of the latest bill (before it was passed) and because of the timing the IRS was to use the latest return they had on file and if things changed (like in your case) they can not ask for the money back. I do not know about the 1400 payment that your son received. I think he'll be able to keep it but I don't remember what the bill said about your situation. I'm sure your accountant will sort it out.
In my case the IRS didn't see the little box checked on my daughters return that she was claimed on my return. In my case I will need to send the money back because she should not have received the 2 payments in 2020 because she was a dependent on my return.
