Sale of primary residence

My wife and I purchased our primary residence in 2007 and sold it in 2020 for a small profit which was much less than the $500,000 exclusion.   It was never rented out, never used as an office deduction and we lived in it continuously as a primary residence from 2007 until 2020.  We've answered all the questions appropriately in Turbotax but the software tells us that we "don't qualify for an exclusion of the gain on the sale of your home".  What are we doing wrong?  Thank you.