Deductions & credits

I have the same problem with Form 1040/1040SR WKS. TT Deluxe is entering the incorrect value on line 12b and will not allow me to correct it.

 

The situation in detail:

 

TurboTax Deluxe (Desktop) is taking Standard Deduction, which is correct.

 

Filing: Married Filing Jointly

 

Amount on Line 12a correctly reflects my standard deduction

 

Below Line 12a below instructions, "Enter the smaller of these cash contributions made or $300 ($600 if married filing jointly on 12b below if you take the standard deduction", the amount is $358.

 

So based on the instructions the correct amount for line b appears to be $358 (the smaller of the cash contributions or $600 for MFJ). BUT, TT keeps entering $300 in red.

 

If I change it to $358, final review complains, and when I look back at line 12b, it is changed back to $300 in red. It seems like there is nothing I can do to make this line $358.

 

Can someone please tell me what I'm doing incorrectly or else please correct the program to enter the correct value. I believe that TT should enter $358 in box 12a or at least allow me to do so.