FHA Loan Initial Disclosures show a lower LTV with a reduction in the MIP Factor.
Appraisal comes in low. The impact is not to renegotiate the SP. Impact is a higher LTV impacting a higher MIP factor.

Is this is a COC ( within 3 days)?

Assume this impact did not change the APR by .125+, is the initial CD an acceptable time to correct this variable to the borrower?
No TILA Violation because the prior disclosures are not the final or actual. Acting in Good Faith is another question.

Assume the Lender wants to show Good Faith by recognizing the issue beyond the 3 days COC. A reduction in the rate to compensate for the increase finance charge and increase mo. mi payment should demonstrate the lenders intent to act in good faith by keeping the borrower total payment in line with the early disclosures.

This action would then constitute a conflict of fair lending practices in order to align or act in good faith.

Are we missing the forest thru the trees on this?