"When I enter them correctly, turbotax is not adjusting the basis?"
You can enter each improvement separately under Assets/Depreciation in the Rental Properties section of the program but then you will have to "sell" each one separately (i.e., assign a sales price to each asset) and you do not take a depreciation deduction for assets purchased and disposed of in the same tax year.
You can also add the total cost of all improvements made during 2019 (the year the improvement was made and the sale) to your cost basis in the program. You would add the improvements and cost manually and type that figure into the program. However, you need to note the accumulated depreciation figure prior to adding the cost of the improvements to your cost basis so that the cost of improvements are not calculated by the program for the purposes of depreciation.
