Retirement tax questions

I am using 2020 turbotax deluxe and inputting seven 1099-B's.  I input values for proceeds and cost exactly as were provided to me.  They are automatically rounded up or down on form 8949 correctly.  BUT when all the transactions are totaled up, what should have been rounded up was rounded down and what should have been rounded down was rounded up.  Three different tech support persons could not help.