I did not receive my 2nd stimulus. My ex claimed son last year and got his stimulus. When I try to get my 600 rebate, it says1200 and I cant change it.

[KrisD15]

One Child, Two Payments

Yes, in your situation, you will both get the stimulus for the same child. 

[VolvoGirl]

So you get 600 for you and 600 for the child even though he got it last year.