“Factors” for bond pricing are not handled by Quicken UNLESS the financial institution sends a quote with the factor included in the calculation of current price. Some do (apparently) and some don't. What financial institution holds the Account the TIPS is in? With the popularity of these bonds these days they might be willing to send the factor adjusted price if enough people ask for it.
In the meantime though you'll have to enter the adjusted quote figure by hand for accuracy.
It's Vanguard.
Where do I enter the factor?
You don't “enter” the factor in Quicken, you use the factor, combined with the quote provided, to come up with the correct price of the bond.
Apparently Fidelity does it correctly: