I have clients (MFJ) with TY2020 AGI of $59,885. Their tax return shows a refund of $1,036. When I input the long term capital gain of $10,000 from the sale of a home, never their primary residence, their refund shrinks to $886. I am confused, as it is my understanding that LT capital gains are taxed at 0% for MFJ returns with less than $80,000 in AGI. What am I missing?