Backdoor Roth IRA tax withhold, now 8606 form is not adding up

Messed backdoor roth ira. The correct way is to convert and select not withhold tax. But someone in my family messed up and clicked yes to that question for their backdoor.

 

Now the 1099 is saying

  • Box 1 = $7240
  • Box 2B = X,
  • Box 4 = $724 withhold.
  • Box 7 = 2X

After playing around with Turbotax, I got it to work in the Taxable IRA Distribution worksheet (8606 has a note saying Using such worksheet).

Line 1, 7000 (into Traditional)

Line 2, Previous year basis 0.

Line 4, $6 (End of year left with 6 dollar)

Line 5, $724 (messed up the 10% withholding)

Line 6 $0 (this is where I think either the Turbotax software or 1099R is wrong) It should not be 0, it should be ($7240-$724)

I cannot get it to work, I wish I can just type it in, but the button take me back to 1099R, not allowing me to edit this.
At the end it said I have 0 taxable, which is not true.

I should be paying around 7240 - 7000 = 240 worth of taxable, rough math not counting that 6 dollar left over.