You're right, the non-reported Box B transaction was only one line but I inserted it when I was inserting all the other ones (summarized as well, but of type A and D) and I might have picked the "Summarize" option by mistake. I already filed to the IRS so I'll have to send the Form 8453 unluckily. I just wanted to be sure that I don't need to send the hundreds of pages of the 1099-B for all the other transactions, thank you for confirming it.
