Tax refund -- trying to determine where it's coming from, or where I screwed up

I have approximately $8k in total refund (Federal and state) and not sure where it's coming from and am trying to verify it's accurate before I file. I'm using TurboTax.

W2 income: $214,434 (my wife and I, filing jointly)

• Job 1: $125k (6 months), $32,773 in federal tax withholding
• Job 2: $32,366, $2,241 in federal tax withholding
• Job 3: $56,867, $3,720 in federal tax withholding

Total federal tax withheld: $38,734

SE income: $19,787

SE estimated taxes paid: $0 (included in an add'l withholding of $750 per paycheck on Job #1, this add'l withholding is included in number above)

Taking standard deduction.

The only thing I can think of is Job #1 withheld too much, and then I accidentally added on more assuming I'd need to cover SE income? It was $2106/paycheck before add'l withholding, but that's still only 20% of my income.