Amended Return Questions

I submitted 2024 tax returns for both state and federal. A few weeks later, I received an additional 1099 for about $800 (interest earned). I figure I have to submit an amended return to include this additional 1099. I started the amendment and it looks like I will owe over $600 in tax with seems crazy for an additional $800 in interest income.  My overall household income is around $105000.  What am I missing?