Why can't TT figure out 1040 Wks line 10 b by itself ?

I'm getting an error on review which complains that 1040 Wks line 10 b is blank.

Can TT not correctly figure out and automatically fill in 1040 Wks line 10 b by itself ?
Am I really supposed to have to switch from EasyStep to Forms view and manually fill in that line myself ?

I've entered my charitable and other deductions and the standard deduction is better for me than itemizing. My charitable deductions were more than $300 but shouldn't TT have all the information to put $300 into the 1040 Wks line 10 b for me ? (I mean it did figure out the standard deduction was better than itemizing)