2020 wages: 23,469, Federal with held: 1,710 = Federal refund: 679 2021 wages: 40,081, Federal with held: 3,170 = Federal refund: 66. Seems off? Why so small?

The rest of my tax situation is virtually the same, in comparing the 2 years.  Can someone please explain why my Federal refund is so small?  I want to be sure that I did everything correct before I file.