I can try to break it down for you. One child must have turned 17 in 2020. So Turbo Tax is saying you should have got 2400 for married plus 500 for 1 Dependent = 2900. And 3 people for the second one 3x600=1800.
For the IRS, looks like they are just showing for 1 spouse and 1 Dependent. 1200+500=1700 and 2 people x 600=1200. Don't know why that is not including the other spouse.
The 3400 and 2400 you already got is more. You don't have to pay any back. Just don't try to claim any again on line 30.
