How are you entering the income? Are you simply an investor? Did you materially participate in prior years? Is there a code in box 14?
If in box 14 there is a letter A, then this is saying your income is self-employment income. Self-Employment income is subject to SE Taxes. To be self-employed, means you are employed and participating. This would need to be changed on your K-1 in order for it not to be subject to SE Taxes.