My itemized deductions are more than $5,000 above the standard deductions for my family but TT says the amount of refund is identical. What could be causing this?

There comes a point where adding more deductions will not do anything more for your return. Once the itemized deductions have reduced your taxable income to zero adding more deductions cannot make it less zero.  Review the actual return to see if this is your case.

Are you looking at the Gross deductions?  Not all of them (such as Medical) count at 100%.

Also be aware that the IRS may question how you have deductions of  close to $30,000 on a $45,000 income.