I think we are drifting away from the real issue; suggest not focusing so much on Form 8812 (even thought that is what the IRS notice stated).
All the calculations related to the Child Care Credit are automated, with one exception. That exception is how much you received from July - Dec, 2021 in what is called 'the advance child tax credit'.
SInce you have two children between the ages of 6 and 17 (using their ages as of 12/31/21), you are entitled to a $6,000 Child Care Credit (assuming they are US citizens or Resident aliens and lived with you for at least 6 months of 2021).
But that $6,000 is reduced by whatever you received from Jul - Dec. 2021.
Since you state that Line 28 is $4500 that infers that you told TT that you received $1500 during that time period. Is that accurate?
Note that you should have received Letter 6419 stating how much the IRS sent you, but BE CAREFUL, there were TWO letters, once addressed to you and one to your spouse and you were to ADD THE TWO LETTERS TOGETHER.
Please check your records (bank accounts) and confirm whether you received $500 per month (which is what I suspect) or only $250 per month.
if you received $500 per month, THAT is why the IRS sent you the letter indicating that Form 8812 was incorrect. Their records indicate they sent you $3000 but you only entered $1500 into TT.
is that what occured? if so, there is nothing for your to do (unless the letter from the IRS states otherwise) as the IRS will reduce your refund by the $1500 discrepancy (or increase what you owe)
