You have $1,800 on 1040 line 30? Maybe you answered it the wrong way. I got the 600 on my father's return.
I'm sure you didn't claim any dependents on his return? And you didn't do him as Married Joint?
Try going back through the stimulus section.
After you have entered your tax information and are ready for the Federal Review, it will be the first question.
If you are trying to trigger it, you can go to Other Situations, answer any questions and click Done. The next automatic selection is Federal Review and it will ask about payments received.
