I have 2 dependents and total childcare expenses of $12k, with $4k paid for by FSA. AGI over $43k. Any reason Turbotax gives me $420 instead of $1,200? What am I missing?

My understanding is I should be getting 20% of $6,000 as I still have $8k eligible expenses after the FSA comes off the top. One dependent was born in the year and has no expenses if that makes any difference. Are there any other factors I have not considered?