When using the "actual cost " for determining business use of home expenses, TurboTax is capping business expenses, disallowing and carrying over most expense.

We have a studio Apartment used while we work - 51% of that space is the "home office", with Total expenses for the entire space adding up to more than $10,000, Using schedule 8829 we manually calculate an amount to enter on line 30 of schedule C that is three times higher than that allowed by turbotax. I have read the IRS rules and do not find a cap.