I didn't have any transactions for which I didn't receive a 1099B. TurboTax seems to be creating it from the K1, since it has the same Description of Property information.
I wasn't able to delete the form without TurboTax re-creating it, but I took your suggestion to just delete all the information on the form (Copy 3), and that seemed to do the trick. TurboTax didn't re-create the form again.
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