Many thanks for the detailed response.
It seems the main (perhaps the only) problem is that Turbotax did not look at the detailed worksheets for Form 8949 from IBKR as their consolidated Form 1099 stated that for Box B category (Noncovered Securities) the only item known is the Proceeds. So the Category B transactions from IBKR listed by TT have nil cost and nil adjustment, but not those from Fidelity
I think it may be easier to enter these missing data on Forms for Box B category. If even after this correction the totals don't agree with the data on Schedule D, I have to search for other problems. Luckily, TT seems to have listed all transactions (too many, I now realize) from the Brokers, so I don't have to type them.
