Deductions & credits

@deetrumpet  Exactly the same problem with 2021 TT Basic.  This is definitely a TT accuracy problem.  Work-around don't change that truth.

When I do the Review tab, "Let's make sure your taxes are correct", TT changes it back to $300 causing a decrease in my refund.   Clicking through a few Continues comes to "Let's Check These Entries" and clicking on "Check Entries" shows the $300 in red.  I change it back to $600.  Refund goes back up and I click on "Run Smart Check" and all is well, and TT proceeds to go to the filing screens.  But if I ever make a change and rerun the "Federal Review", TT changes it back to the incorrect $300 without notice.  

Hey, I copied the following screen shot from the TT program.  What is this "100% accuracy guarantee" and how to I make a claim?  At a 25% marginal tax rate, the $300 mistake would cost me $75.