There are several reasons you may see no change.
Since the program starts out with the standard deduction, you won't see any change until the TOTAL of all your itemized deductions exceeds your standard deduction. For example, if you're married filing jointly, your standard deduction is $12,600.
The amount of many deductions can also be limited. For example, you can only get a deduction for the amount of medical expense that exceeds 10% of your Adjusted Gross Income (7.5% if 65 or older.)
For property tax, there's always the chance you're paying AMT, in which case the tax amount is added back to your taxable income for AMT so you'll see no change for that deduction.