Good question. I saw that the Ein Yaakov uses the male term for both. This could be explained by the fact that the Gemara is keying on (Atziras) Nekavim that are blocked, and the word Nekavim is male. However, I did not see an explanation for the text of our Gemara. Once I see that there is a different text in the Ein Yaakov, I personally would lean towards thinking this is possibly a mistake (and with words such as these it is not uncommon that these mistakes may occur, as Rav Reuven Margoliyos states in many places, such as in his Sefer Mechkarim B'Darchei ha'Talmud). However, I cannot say this conclusively.

All the best,

Yaakov Montrose