@george1550 need more info --
(a) assuming -- tax payer / owner of foreign prop. is a US person ( citizen/GreenCard/Resident for Tax purposes); 2nd home disposition was entered per usual i.e. Schedule-D ( Acquisition date , disposition date , adjusted basis , gross sales proceeds etc. ), resulting in a capital gain per US Tax laws; No other foreign income reported; form 1116 was done per step-by-step using the lesser of foreign capital gain and US capital gain, foreign income tax reported is paid / accrued .
(b) Did you go into forms mode and see the form 1116 ( form 1116 comp. worksheet ) showing the gross foreign source income ? Is this where you are finding the error ? Did you use any adjustments to "gross foreign source " income while entering the details ?
I am asking all these Qs and including my assumptions because based on your answers we may be able to see why TurboTax is misbehaving. The more you tell me about the situation and where you entered the data, the more accurate my response is likely to be. As you can see , I do not have any clue off the top -- you appear to have done the needful and yet Turbo seems to think otherwise.
Will circle back once I hear from you