This is a known issue that is now resolved.
Here are the steps I recommend that you follow to have the $300 appear in Form 1040, Box 10b:
- Click Deductions and Credits
- Select Review/Edit
- Click Edit to the right of Standard Deduction
- Click OK, Sounds Good
- Click Wrap Up Tax Breaks
- Click Continue
- Make sure that $300 is filled in and then click Continue
- Click Lets Keep Going
- Now go to the 1040 Preview and your $300 should be on Line 10b.
