taxes on interest earned from savings account for student with total income for year less than $5,000

My son(17) worked a part-time job last year and received a W-2 his earnings(box 1) was about $3,900 and Fed taxes(Box 2) withheld was about $250, no state taxes withheld.  He also had interest income(1099-INT) from a saving account of about $800.  His total income is well below the Fed minimum taxable income of $14,600 for 2024.  I assumed since his total income was below the Fed minimum that he would be refunded all fed taxes he paid in 2024(~$250).  However,  it seems that TurboTax calculated and expects that $29 of taxes should be paid on his interest income and is reducing his refund from $250 to $221.  Is that correct?