Regarding the `Limited amount to report on Sch A, line 8a`, sometimes TurboTax won't auto fill it and fails the final check. I found it should be the same value as `Sum of lines 5a through 5d below` field above if your loan is not over the limits by IRS and the portion not being used towards the property are handled correctly. Otherwise you need to put the value accounting for limitations.
(Disclaimer: I'm not a tax professional. Take my opinion at risk.)
