Amended returns of 2018, 2019, 2020 due to child without SSN during those years

I was unaware of prohibitions of claiming EIC and Child Tax Credit for children who did not have an SSN for the filing year, else I would have done it without delay. However, in 2020 I had proceeded to procure an SSN for my son, however the SSN was not issued until 2021 due to government offices closed/understaffed. 

 

Anyway, for the 2018 Amended return, it was finally "Adjusted," and I got a notice indicating "you cannot retroactively claim Child Tax Credit and Earned Income Credit."

 

With that, is only the CTC and EIC affected? Meaning I can still get some sort of deductions/credit for my newborn son who obviously lived with me for that year, and for 2019?

 

I am sure the same will be for the 2019 1040X, and 2020, but for the 2020 rejection (if there is one), I do plan on appealing up to going to tax court if I have to because the delay of getting the SSN for 2020 was NOT MY FAULT. I have plenty of documentation including emails showing they could not process my request for an extended time due to office closures and/or staffing shortages due to pandemic. 

 

Since I will not get the CTC and EIC for 2018, and 2019, the main question is, about any other deductions/credits for those years for my child? 

 

Thanks!