The 1099b cost basis provided by your financial broker, should likely be adjusted (using f8949 column e/g), so it matches the cost basis as shown or calculated from the K-1. item 11c losses or gains from K-1 will flow to form 6781. Assuming you sold all shares, it should net out between the revised 1099b and f8949 on schedule D. If you are holding PTP ETF shares over multiple years, there may be carryover between years, which will net out on the final year of selling shares. Yup, it's confusing. Consult your tax advisor.
