Why am i not getting credit for my mortgage interest paid?

This year, the standard deduction increased substantially. If your itemized deductions do not exceed the amount of the standard deduction, you will get the standard deduction vs. summing up itemized deductions.

I have enough to itemize my deductions. I paid Interest on my mortgage and entered the amount shown on form 1098; however, it shows up as $0.00 on schedule A LINE 8Aa. Why? 

I have enough to itemize.